id="p">P

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P1

See Protocol 1.

P2

See Protocol 2.

pacing

In SNA, a technique by which the receiving system controls the rate of transmission of the sending system to prevent overrun.

package

(1) In Java™ programming, a group of types. Packages are declared with the package keyword. (Sun)

(2) A control structure that is produced during program preparation and that is used to execute SQL statements or XQuery expressions.

(3) A function that allows an application programmer to collect all the parts of an application together for distribution.

packed decimal format

Representation of a decimal value in which each byte within a field represents two numeric digits except the far right byte, which contains one digit in bits 0 through 3 and the sign in bits 4 through 7. For all other bytes, bits 0 through 3 represent one digit; bits 4 through 7 represent one digit. See also zoned decimal format.

packed decimal item

In COBOL, a numeric data item that is represented internally in packed decimal format.

packed field

A field that contains data in the packed decimal format.

packed key

A key field in packed decimal format.

packet

(1) In data communication, a sequence of binary digits, including data and control signals, that is transmitted and switched as a composite whole. See also frame.

(2) The field structure and format defined in the CCITT X.25 Recommendation.

packet assembler/disassembler (PAD)

A functional unit that enables data terminal equipment (DTE) not equipped for packet switching to use a packet-switched network.

packet level

A part of X.25 communications that defines the protocol for building logical connections between two DTEs and for moving data on these connections.

packet mode host

Any non-SNA, X.25 host system.

packet rules

Functions that help keep a network's security from being compromised. Packet rules (formerly called IP packet security ) uses methods such as filtering and network address translation.

packet-switched data network (PSDN)

A communications network that uses packets to send data.

packet switching

The act of sending and routing packets from source to destination based on information contained in their heading record.

packet window

A specified number of packets that can be sent by the DTE before it receives an acknowledgment from the receiving station.

pad

To fill unused positions in a field with dummy data, usually zeros or blanks.

PAD

See packet assembler/disassembler.

padding character

In COBOL, an alphanumeric character used to fill the unused character positions in a physical record.

PAG

See process access group.

page

(1) To move information up or down on the display.

(2) To transfer instructions, data, or both between active physical memory and external page storage.

(3) In the graphical data display manager (GDDM®) function, the picture or chart. All specified graphics are added to the current page. An output statement always sends the current page to the device.

(4) A unit of storage equal to 512 bytes in complex instruction set computer (CISC) systems, and 4096 bytes in reduced instruction set computer (RISC) systems. A page can be moved between auxiliary storage and main storage.

page body

In COBOL, that part of the logical page in which lines can be written, spaced, or both.

page definition

An Advanced Function Presentation™ (AFP™) resource that defines the rules for transforming line data and XML data into Mixed Object Document Content Architecture-Presentation (MO:DCA-P) data and text controls.

page down

To move to the information below the information currently shown on the display. See also page up.

page fault

A program interruption that occurs when an active page refers to a page that is not in memory.

page frame

A 512-byte block of main storage on a 512-byte boundary.

page-in

The process of moving a page from auxiliary storage to main storage.

page layout

In AFP Utilities, a printout format of a page in the printout format definition (PFD). By using the print format utility, the user can design the page layout by placing and repeating a predefined record layout with constant data.

page-out

The process of moving a page from main storage to auxiliary storage.

page printer

In AFP support, any of a class of printers that accepts composed pages, constructed of composed text and images, among other things. See also line printer.

page segment

An AFP resource object containing text, image, graphics, or bar code data that can be positioned on any addressable point on a page or an electronic overlay.

pages per side

See multiple up.

page up

To move to the information above the information currently shown on the display. See also page down.

paging behavior

In capacity planning, the paging characteristics for the transaction. Users can define paging characteristics for any transaction.

paging coefficient

In capacity planning, a number that indicates the amount of paging performed by a transaction in a workload. The higher the number, the more page faults generated. This number is not the number of page faults, but a representation of the total amount of paging.

paging exponent

In capacity planning, a value used to determine the effects of pool size changes. The greater the paging exponent, the greater the change to synchronous reads (page faults) as memory size changes.

paired data

In Business Graphics Utility and the GDDM function, data that is specified so that every X value has only one Y value associated with it. See also nonpaired data.

panel

A formatted display of information on a screen that can also include entry fields.

panel assembly

The hardware parts making up the operator panel, control panel, or indicator panels.

Panel Definition Markup Language (PDML)

A tag language that defines a language for describing user interface elements and layouts. PDML is based on the Extensible Markup Language (XML). PDML files are used with the Graphical Toolbox components within the iSeries™ Toolbox for Java to simplify the construction of user interfaces within Java. You can use PDML and the Graphical Toolbox components to build and run Java applications on any Java compliant platform.

panel format

In query management, the format of the data in an externalized query or procedure file.

panel group

An object that contains a collection of any of the following: display formats, print formats, or help information. The system-recognized identifier for the object type is *PNLGRP.

PAP

See Password Authentication Protocol. See also Challenge Handshake Authentication Protocol.

paragraph

In the Procedure Division of a COBOL program, a name followed by a period and a space and by zero, one, or more sentences. In the Identification and Environment Divisions, a header followed by zero, one, or more statements.

paragraph header

In COBOL, a reserved word, followed by a period and a space that indicates the beginning of a paragraph in the Identification and Environment Divisions.

paragraph name

In COBOL, a user-defined word that identifies and begins a paragraph in the Procedure Division.

parallel session

Two or more concurrently active sessions between the same two network addressable units using different pairs of network addresses or local-form session identifiers. Each session can have independent session parameters.

parameter (parm)

A value or reference passed to a function, command, or program that serves as input or controls actions. The value is supplied by a user or by another program or process.

parameter list

A list of values that provide a means of associating addressability of data defined in a called program with data in the calling program. It contains parameter names and the order in which they are to be associated in the calling and called program.

parameter marker

A question mark (?) that appears in a statement string of a dynamic SQL statement. The question mark can appear as a typed or an untyped parameter marker where a host variable might appear if the statement string were a static SQL statement.

parent class

A class from which another class inherits instance methods, attributes, and instance variables.

parent directory

The directory one level above the current directory. An object's parent directory is the directory that contains the names and controlling information for the object. If the object is named in more than one directory, it has multiple parent directories.

parent file

The file in a constraint relationship that contains the parent or primary key. See also dependent file.

parent key

(1) A field or set of fields in a database file that must be unique, ascending, and may or may not contain null values. The parent key may be the same as the primary or unique key.

(2) A primary key or unique key that is used in a referential constraint. The values of a parent key determine the valid values of the foreign key in the constraint.

parent process

A process that is created to carry out a request or set of requests. The parent process, in turn, can create child processes to process requests for the parent.

parent row

A row that has at least one dependent row. See also dependent row.

parent table

A table that is a parent in at least one referential constraint. See also dependent table.

parent window

In some operating systems, the window that controls the size and locations of its children. If a window has children, it is a parent window.

parity

The state of being either even-numbered or odd-numbered. See also parity bit.

parity bit

A binary digit added to a group of binary digits to make the sum of all the digits either always odd (odd parity) or always even (even parity). See also parity.

parm

See parameter.

parse

To break down a string of information, such as a command or file, into its constituent parts.

part

In VisualAge® RPG, a self-contained software object consisting of a set of external features that allow the part to interact with other parts. The parts on the VRPG palette can be used a templates to create controls.

partial call

A two-party call in which one of the two parties is a virtual party; this can be viewed as a transient stage of the telephone call.

partition

(1) On a personal computer hard disk, one of four possible storage areas of variable size; one may be accessed by DOS and each of the others may be assigned to another operating system.

(2) A subset of the active cluster nodes that result from a network failure. Members of a partition maintain connectivity with each other.

(3) A logical division of storage on a fixed disk.

partitioned data set (PDS)

A data set on direct access storage that is divided into partitions, called members, each of which can contain a program, part of a program, or data. See also sequential data set.

partner logical unit

In SNA, the remote participant in a session.

parts catalog

In VisualAge RPG, a collection of parts defined by the user. Parts in the catalog can be moved to and from the parts palette.

parts palette

In VisualAge RPG, a collection of views and models used in building additional parts for an application. Application programmers can add parts to the palette for use in defining applications or other parts.

party

In telephony, an addressable end point of a telephone call.

PASA

See program automatic storage area.

passive attack

In computer security, an assault on a network that is difficult to detect and involves an intruder who taps into or traces communications. Sniffing is an example of a passive attack.

passive open

In TCP/IP, the state of a connection that is prepared to provide a service on demand. See also active open.

password

In computer and network security, a specific string of characters used by a program, computer operator, or user to access the system and the information stored within it.

Password Authentication Protocol (PAP)

A type of authentication where the user name and password are transmitted in an unencrypted form. This is a more basic form of authentication than Challenge Handshake Authentication Protocol (CHAP). See also Challenge Handshake Authentication Protocol.

password level

Within DST, a property that specifies whether Data Encryption Standard (DES) or Secure Hash Algorithm (SHA) encryption is used when storing passwords. The default level is DES.

password protection

In APPC, the support that uses protected passwords to keep user passwords secure. The LU type 6.2 architecture refers to password protection as password substitution.

password server

A server that allows clients to change their password on the key distribution center (KDC) remotely. The password server typically runs on the same machine as the KDC.

patch cable

A length of cable with data connectors at both ends; it is normally used to interconnect two sections of building cable at a distribution panel or to connect a product to the building cable.

path

(1) In a network environment, the route between any two nodes.

(2) In SNA, the set of data links, data link control layers, and path control layers that a path information unit travels through when sent from the transmission control layer of one half-session to the transmission control layer of another half-session.

(3) In OSI, a description of how a local line or line set can be used for outbound communications.

(4) The route through a file system to a specific file.

path assignment

In OSI, the permanent assignment of a DTE at an adjacent node to a path. This restricts the path to particular lines to be used for connections to or through that adjacent node.

path code page

A list of the path name components of the files that are exported to and mounted on a specified Network File System (NFS) client or netgroup.

path control layer

In SNA, the layer that routes all messages to data links and half-sessions.

path control network

In SNA, the functional layer that includes the data link control and path control layers.

path information unit (PIU)

In SNA, the smallest amount of data that the system sends out on a communications line, consisting of a transmission header followed by a basic information unit or a basic information unit segment.

path name

(1) The name of an object in the integrated file system. Protected objects have one or more path names.

(2) A name that specifies all directories leading to a file plus the file name itself.

path set

In OSI, a set of paths grouped by the similarity of their requirements. OSI Communications Subsystem requires that each line be assigned to a line set. If the line is to be used for outbound communications, then its associated line set must be assigned to a path set. A line that is not assigned to a path set (through a line set) can be used only for inbound communications.

path set sequencing

In OSI, the process of defining the sequence in which lines are to be selected for outbound connections.

pattern

In REXX, the parts of a parsing template that allow a string to be split by the explicit matching of strings (literal patterns) or by the specification of numeric positions (positional patterns). Parentheses may be supplied to create a variable pattern, a pattern whose value is derived from a variable.

pattern-matching character

See wildcard character.

pawl

(1) A pivoted tongue or sliding bolt adapted to fall into notches on a machine to permit motion in only one direction.

(2) The tongue of a ratchet.

PBX

See private branch exchange.

PCC

See power control compartment.

PC file

A file stored on a personal computer.

PCI

See Peripheral Component Interconnect. See also Peripheral Component Interconnect-X.

PCI bridge

A device that connects one or more subordinate PCI buses to a primary PCI bus. The PCI bus that is closest to the system processor is the primary PCI bus, and the subordinate buses are secondary PCI buses.

PCI bridge set

A set of PCI card positions.

PCI-X

See Peripheral Component Interconnect-X. See also Peripheral Component Interconnect.

PC-mixed character set

A character set that contains a mixture of single-byte character set (SBCS) PC code pages and double-byte character set (DBCS) PC code pages.

PCML

See Program Call Markup Language.

PC session

An operating session that uses DOS and other IBM® programs on a personal computer attached as a 5250 work station to a server.

PCT

See program control table.

PDA

See personal digital assistant.

PDF

See Portable Document Format.

PDF subsystem

The IPDS™ to PDF Transform function of IBM Infoprint® Server for iSeries. One or more PDF files are generated from an Intelligent Printer Data Stream™ (IPDS), Advanced Function Presentation (AFP), or SNA character string (SCS) spooled file and then sent as e-mail, spooled for printing, or stored in the integrated file system as a stream file. A mapping program can be used to implement intelligent routing of the PDF subsystem output. See also intelligent routing, mapping program, mapping object.

PDM

See Programming Development Manager. See also 5250 display.

PDML

See Panel Definition Markup Language.

PDN

See public data network.

PDS

See partitioned data set. See also sequential data set.

PDU

See protocol data unit.

PDV

See presentation data value.

PDV report

In OSI, an output file produced by the Abstract Syntax Checker that shows the names of the PDVs in the input module and the data structures that comprise them.

peer

A general term for the corresponding node or entity with which one communicates.

peer application entity

In OSI, the corresponding application entity with which a local application entity communicates.

peer entity

In OSI, an entity within the same layer.

pending

Pertaining to a submitted request that is awaiting processing.

PEP

See program entry procedure. See also user entry procedure.

percolate

To decline to handle an exception. The unchanged exception is passed on to the next exception handler.

performance

A measure of a system's ability to perform its functions, including response time, throughput, and number of transactions per second.

performance data

Information about the operation of a system or a network of systems that can be used to understand response times and throughputs and to predict the effects of certain system operational changes or programming changes.

performance management

The discipline that encompasses capacity planning, collecting performance data, and tuning resources.

Performance Management for eServer™ iSeries (PM eServer iSeries, PM iSeries)

A function of the i5/OS® operating system that provides automated collection of performance data, that reduces the data daily, and that manages the amount of storage that is used by the collected data. This function was previously known as Performance Management/400 (PM/400).

Performance Tools

The IBM licensed program that allows a user to display, report, graph, and analyze performance data.

per-hop behavior

A description of an external and observable forwarding treatment. Routers use the per-hop behavior code points to give network traffic a certain priority. A per-hop behavior is applied to each Internet Protocol (IP) packet when differentiated services is designated. The six bits of the differentiated services code-point field designate the per-hop behavior.

Peripheral Component Interconnect (PCI)

A local bus that provides a high-speed data path between the processor and attached devices. See also Peripheral Component Interconnect-X.

Peripheral Component Interconnect-X (PCI-X)

An enhancement to the Peripheral Component Interconnect (PCI) architecture. PCI-X enhances the Peripheral Component Interconnect (PCI) standard by doubling the throughput capability and providing additional adapter-performance options while maintaining backward compatibility with PCI adapters. See also Peripheral Component Interconnect.

permanent error

An error--for example, a hardware component failure--that can be corrected only by external intervention. See also transient error.

permanent event

In OSI, an event that indicates the occurrence of an irrecoverable error--one that makes a resource unavailable or causes OSI Communications Subsystem to stop. Permanent events are logged and generate a message to the operator. See also transient event.

permanently maintained path

In OSI, a CLNS path to an adjacent node that is maintained until OSI Communications Subsystem is restarted.

permanent object

An object, such as a database files or program, that stays in the system until a user with the required authority deletes it.

permanent virtual circuit (PVC)

A virtual circuit that has a logical channel permanently assigned to it at each data terminal equipment (DTE). A call establishment protocol is not required. The permanent virtual circuit establishes the identity of the called party within the network services contract.

permission

The ability to access a protected object, such as a file or directory. The number and meaning of permissions for an object are defined by the access control list.

persist

To be maintained across session boundaries, usually in nonvolatile storage such as a database system or a directory.

persistence

A characteristic of data that is maintained across session boundaries, or of an object that continues to exist after the execution of the program or process that created it, usually in nonvolatile storage such as a database system.

persistent

Pertaining to data that is maintained across session boundaries, usually in nonvolatile storage such as a database system or a directory.

persistent message

A message that survives a restart of the queue manager. See also nonpersistent message.

persistent object

An object whose state can be preserved beyond the ending of the process that created it. Typically, persistent objects are stored in files.

personal digital assistant (PDA)

A handheld device that is used for personal organization tasks (such as calendaring, note-taking, and recording telephone and fax numbers), and networking functions such as e-mail and synchronization.

personal identification number (PIN)

In Cryptographic Support, a unique number assigned by an organization to an individual and used as proof of identity. PINs are commonly assigned by financial institutions to their customers.

personal settings

A choice that allows a user to display or change the characteristics or properties of an object. For example, a user can customize the interface by specifying how the menu bar, status area, and information area are displayed.

PFD

See printout format definition.

PFU

See print format utility.

PGR

See presentation graphics routines. See also Graphical Data Display Manager.

phantom row

A table row that can be read by application processes that are executing with any isolation level except repeatable read. When an application process issues the same query multiple times within a single unit of work, additional rows can appear between queries because of the data being inserted and committed by application processes that are running concurrently.

phase encoding

A magnetic recording method in which each storage cell is divided into two regions that are magnetized in opposite directions; the sequence of the magnetic direction indicates whether the binary character represented is 0 or 1.

Phase II negotiation

A negotiation that establishes Security Associations (SAs) that protect your data exchanges. A Phase II negotiation is governed by data policies.

Phase I negotiation

A negotiation that establishes the protection suite for the Internet Key Exchange (IKE) messages themselves. A Phase I negotiation determines how to protect a Phase II negotiation. A Phase I negotiation is governed by key policies.

phonetic

Relating to spoken language or speech sounds.

phrase

(1) An ordered set of one or more consecutive COBOL character strings that forms part of a clause or a Procedure Division statement.

(2) One or more words that together form a unit that is to be searched for in the content of a document.

physical circuit

A circuit established without multiplexing. See also virtual circuit.

physical data block

A string of data elements or a group of records that is received, recorded, processed, or transmitted as a unit.

physical device

An I/O device that is assigned to a logical partition and that is used directly.

physical disk I/O

In Performance Tools, a disk operation for reading or writing data.

physical file

A database file that describes how data is to be presented or received from a program and how data is actually stored in the database. A physical file contains one record format and one or more members. See also logical file.

physical file member

A named subset of the data records in a physical file.

physical interface

A device for a given system, such as an I/O adapter for a token-ring network or an Ethernet network, that provides the physical connection to a network.

physical layer

The OSI layer that provides the mechanical, electrical, functional, and procedural means to start, maintain, and deactivate physical connections for transmissions between data-link entities.

physical level

In X.25, a standard that defines the electrical, physical, functional, and procedural methods used to control the physical connection between the data terminal equipment (DTE) and the data circuit-terminating equipment (DCE).

physical page

In COBOL, a device-dependent concept defined by the action taken by a printer when a new page is requested.

physical resource

In OSI, any resource of a computer available to do work, such as the processor, main storage, or a line. See also logical resource.

physical services header (PSH)

An X.25 protocol used by IBM Systems Network Architecture (SNA) data terminal equipment (DTE). Physical services header provides address services for physically connected systems or devices. The System i™ family does not support PSH. See also enhanced logical link control, qualified logical link control.

physical unit (PU)

In SNA, one of three types of network addressable units (NAUs). A physical unit exists in each node of an SNA network to manage and monitor, at the request of a system services control point logical unit (SSCP-LU) session, the resources (such as attached links and adjacent link stations) of a node. See also control point.

physical unit type (PU type)

In SNA, the classification of a physical unit according to the type of node in which it resides. The physical unit type is the same as its node type; that is, a type 1 physical unit resides in a type 1 node, and so on.

pica

A unit of about 1/6 inch used in measuring typographical material.

PICS

See Platform for Internet Content Selection.

picture element (pixel)

The smallest printable or displayable unit that can be displayed. A common measurement of device resolution is picture elements per inch.

picture space

In the GDDM function, the area of the page that contains the graphics.

PII

See program integrated information.

PIN

See personal identification number.

pin

Part of an electrical connection.

PIN check length

In Cryptographic Support, the number of digits from the personal identification number that are verified.

ping

The command that sends an Internet Control Message Protocol (ICMP) echo-request packet to a gateway, router, or host with the expectation of receiving a reply.

PIN translation

In Cryptographic Support, the conversion of a personal identification number (PIN) encrypted under an input PIN-protection key to encryption under an output PIN-protection key.

PIN-validation key

In Cryptographic Support, a key-encrypting key used to encrypt the validation data in the process of creating a customer's personal identification number (PIN).

PIP

(1) See program initialization parameter.

(2) See problem isolation procedure.

(3) See prepare in progress.

PIP data area

A 2000-byte data area that is associated with each prestart job. The PIP data area is used to hold program initialization parameters that are passed on the program start request to the prestart job.

pitch

The number of characters printed per inch.

PIU

See path information unit.

pixel

See picture element.

PKI

See public key infrastructure.

placeholder

The symbol, consisting of a single period in a REXX parsing template, that can be replaced by a value while running a REXX program. A placeholder has the same effect as a variable name, except that no variable is set.

place operation

In AFP Utilities, an operation that defines a page segment or a record layout in an AFP resource.

plaintext

In cryptography, any data that is not encrypted. Encryption transforms plaintext to ciphertext and decryption transforms ciphertext into plaintext.

planar

A hardware part that has (in one or more planes) logic paths, low-voltage distribution paths, or grounding paths of a section of a machine.

platform

The combination of an operating system and hardware that makes up the operating environment in which a program runs.

Platform for Internet Content Selection (PICS)

A specification that enables Internet users to filter the material they encounter when they surf the Web. Users can accept or reject the material according to its ratings. This specification enables parents, businesses, schools, or discerning individuals to block access to inappropriate and objectionable material.

playback

A technique in which a history of all or part of a program is recorded. The recording allows the user to regenerate the input and output in either the forward or backward direction. This technique is used in debugging.

playback sequence

A series of characters or function keys assigned to a single function key to be used instead of typing the sequence each time.

plenum

A space used for environmental air; for example, the space above a suspended ceiling.

plenum cable

A cable that is listed by the Underwriters Laboratory (UL) as having adequate fire resistance and low smoke-producing characteristics for installation without conduit in ducts, plenums, and other spaces used for environmental air, as permitted by National Electrical Code Articles 725-2(b) and 800-3(d).

PL/I

A procedure-oriented language designed for solving complex scientific problems or for running complicated business applications.

PL/I for System i

An IBM PRPQ that is a high-level language available on the server. The PL/I for System i PRPQ is capable of handling a large variety of data structures and easily allows variation of precision in numeric computation.

plot

To represent graphically on a medium.

plotter

A device that uses one or more pens to draw images with lines on paper or other media.

PLU

See primary logical unit. See also secondary logical unit.

Plug and Play

An Intel® standard for the design of PC expansion boards. It enables computers to recognize new peripheral devices without additional configuration steps.

plug-in

A separately installable component of iSeries Navigator. A plug-in adds folders and objects to the hierarchy tree, choices to iSeries Navigator menus, and property pages to the property sheet for a folder or object.

plug-in support

A part of the server that adds client/server function and tools to the iSeries Navigator tree and enhances existing iSeries Navigator function.

ply

A layer of paper.

PM eServer iSeries

See Performance Management for eServer iSeries. See Performance Management for eServer iSeries.

PM iSeries

See Performance Management for eServer iSeries. See Performance Management for eServer iSeries.

POE

See Proof of Entitlement.

point

(1) A unit of measurement used mainly for describing type sizes. Each pica has 12 points, and an inch has approximately 72 points.

(2) The second byte of a DBCS code, which uniquely identifies double-byte characters in the same ward. See also ward.

pointer

(1) A data element or variable that holds the address of a data object or a function. See also scalar.

(2) The symbol shown on a display or window that a user can move with a pointing device, such as a mouse.

pointer alignment

The COBOL compiler's process of positioning pointer items within a group item to offsets that are multiples of 16 bytes from the beginning of the record.

pointer data item

In the COBOL program, a data item in which address values can be stored. Pointer data items can be compared for equality or moved to other pointer data items.

pointing device

An instrument, such as a mouse, used to move a pointer on the display.

point-of-presence

A system that has been identified as a contact point for another subnetwork for the purposes of collecting topology information.

point-of-sale

In retail communications and Point-of-Sale Utility, pertaining to a method of providing information to support sales and of collecting the resulting sales information from retail devices located in stores.

point-of-sale device

In retail communications and Point-of-Sale Utility, a device that, together with the store controller, provides retail transaction, data collection, credit authorization, price information, and other inquiry and data entry functions.

point-of-sale system

In retail communications and Point-of-Sale Utility, a retail environment system consisting of a store controller and one or more point-of-sale devices.

Point-of-Sale Utility (POS)

The IBM licensed program that provides connectivity between the system and retail controllers. In addition, the licensed program provides file conversion capabilities through the retail file conversion system.

point-to-point

Pertaining to data transmission between two locations without the use of any intermediate display station or computer.

point-to-point line

A communications line that connects a single remote station to a computer. See also multipoint line.

point-to-point link

A connection that uses the Point-to-Point Protocol (PPP).

point-to-point profile

A set of data that is used to establish a point-to-point link.

Point-to-Point Protocol (PPP)

A data-link protocol for communication between two computers that use a serial interface, typically a personal computer connected by telephone line to a server.

policing

In QoS, the process of discarding packets (by a dropper) within a traffic stream according to the state of a corresponding meter that enforces a traffic profile.

policy

(1) In the Backup Recovery and Media Services licensed program, a named or otherwise identifiable set of controls used by Backup Recovery and Media Services to manage and control specific operations. A policy is an overriding value that is carried in tables for use as a default in processing backup, recovery, archive, and media management operations.

(2) In QoS, the combination of rules and services. The rules define the criteria for traffic treatment, network resource access, and use.

poll

(1) In Managed System Services, to query devices to determine operational status and to collect system data.

(2) To determine if any remote device on a communications line is ready to send data.

polling

(1) The process whereby stations are invited, one at a time, to transmit.

(2) Interrogation of devices for such purposes as avoiding contention, determining operational status, or determining readiness to send or receive data.

polling interval

The time between the start of each polling session for this system.

polling list

A list of addresses that the host system uses to control the polling of control units or devices on a BSC or SDLC multipoint line. A general polling list contains the addresses of the control units only; a specific polling list contains the addresses of the devices, which include the addresses of the control units.

polyfillet

In the GDDM function, a curve based on a sequence of lines. A polyfillet is a curved line that is tangent to the end points of the first and last lines and tangent to the midpoints of all other lines.

polygon

In the GDDM function, a sequence of adjoining straight lines that enclose an area.

polyline

In computer graphics, a sequence of adjoining lines.

polymorphism

An object-oriented programming characteristic that allows a method to perform differently, depending on the class that implements it. Polymorphism allows a subclass to override an inherited method without affecting the parent class's method. Polymorphism also enables a client to access two or more implementations of an object from a single interface.

pool

(1) A readily available supply.

(2) A designated place to store data.

(3) A division of main or auxiliary storage.

pool database faults

In Performance Tools, the total number of interruptions to jobs that were required to transfer data into the pool to permit the program to process the database data.

pool database pages

In Performance Tools, the total number of pages of database data transferred from auxiliary storage to the pool to permit the program to run.

pool nondatabase faults

In Performance Tools, the total number of interruptions to jobs (not necessarily assigned to this pool) that were required to transfer data into the pool to permit the machine interface instruction to access the nondatabase data.

pool nondatabase pages

In Performance Tools, the total number of pages of nondatabase data transferred from auxiliary storage to the pool to permit the program to run.

pop

To remove an item from the top of a pushdown list. See also push.

POP

See Post Office Protocol.

pop-up menu

A menu that appears as the result of some user action (usually clicking the right mouse button) and that contains choices appropriate for the selected object in its current context.

port

(1) A hardware interface to which an I/O device is attached for the purpose of sending and receiving data.

(2) An end point for communication between applications, generally referring to a logical connection. A port provides queues for sending and receiving data. Each port has a port number for identification. See also node.

portability

The ability of equipment to be transported manually.

Portable Application Solutions Environment

A feature of the i5/OS operating system that provides the ability to run certain UNIX® applications. Programs that run in i5/OS PASE have direct access to PowerPC® instructions and access to i5/OS services such as file system support and sockets support.

Portable Document Format (PDF)

A standard specified by Adobe Systems, Incorporated, for the electronic distribution of documents. PDF files are compact; can be distributed globally via e-mail, the Web, intranets, or CD-ROM; and can be viewed with the Acrobat Reader.

Portable Operating System Interface (POSIX)

An IEEE family of standards designed to provide portability between operating systems that are based on UNIX. POSIX describes a wide spectrum of operating-system components ranging from C language and shell interfaces to system administration

Portable Operating System Interface for Computer Environments

See Portable Operating System Interface.

port group

A group of ports identified by the common carrier with a single DTE address. The network directs incoming calls to the first available port, using a sequential search (rotary) technique.

port number

In Internet communications, the identifier for a logical connector between an application entity and the transport service.

port scan

Software that searches systems in a network for open ports. A port scan is used by administrators to check the security of a network, and by hackers or crackers to gain entry to the network.

POS

See Point-of-Sale Utility.

position

(1) Within a string, the ordinal position of one element of a string relative to another.

(2) Within an attribute, the ordinal position of one value relative to another.

positional parameter

A parameter that must appear in a specified location, relative to other parameters.

positional pattern

In REXX, a pattern that causes parsing to occur on the basis of location within the input string. A positional pattern takes the form of a signed or unsigned whole number.

positive response

In SNA, a reply indicating that a request arrived and was successfully received and processed. See also negative response.

POSIX

See Portable Operating System Interface.

post

(1) To note the occurrence of an event.

(2) To add information in a record to keep that record current.

postamble

A sequence of binary characters recorded at the end of each block of data, on phase-encoded magnetic tape, for synchronization when reading backward.

Post Office Protocol (POP)

A protocol that is used for exchanging network mail and accessing mailboxes.

postoperation exit program

A user-written program that is given control after operation of a system function.

PostScript

A page description language developed by Adobe Systems, Incorporated, that describes how text and graphics are presented on printers and display devices.

Post Telephone and Telegraph Administration (PTT)

An organization, usually a government department, that provides data communication services in countries or regions other than the USA. Examples of PTTs are the Bundespost in Germany and the Nippon Telephone and Telegraph Public Corporation in Japan.

power control compartment (PCC)

The rack component that logically controls the application of alternating current power to the units in the rack.

power down

A CL command to turn the power off and bring an orderly end to system operation.

power-on light

The light on the operator panel that indicates that the DC power in the system is functioning.

PowerPC

A computer architecture that is based on the third generation of RISC processors. PowerPC was developed jointly by Apple, Motorola, and IBM.

PowerPC AS

The processors that implement the 64-bit PowerPC architecture with extensions to support commercial applications for multiple users.

power sequence cable

A signal cable that connects the secondary racks to each other and to the primary rack in a system with more than one rack, and allow complete control of the power from the primary rack.

PPDU

See presentation-layer protocol data unit.

PPP

See Point-to-Point Protocol.

PPP filter identifier

A filter identifier that allows you to apply filter rules to an interface that has been defined in a point-to-point profile. The PPP filter identifier also links the filter rules to groups of users in a point-to-point profile. Because the point-to-point profile is associated with a specific IP address, the filter identifier implicitly defines the interface to which the rules apply.

preamble

A sequence of binary characters recorded at the beginning of each block of data, on a phase-encoded magnetic tape, for the purpose of synchronization when reading forward.

precision

An attribute of a number that describes the total number of binary or decimal digits, excluding the sign. The sign is considered positive if the value of a number is zero.

precompile

To process programs that contain SQL statements before they are compiled. SQL statements are replaced with statements that will be recognized by the host language compiler. The output from a precompile process includes source code that can be submitted to the compiler and used in the bind process.

predefined message

A message with a description that is created and stored in a message file before it is sent by the program. See also immediate message.

predefined value

A fixed value defined by IBM that has a special use in the control language and is reserved in the operating system. A predefined value usually has an asterisk (*) as the first character in the value.

predicate

(1) A Boolean logic term denoting a logical expression that determines the state of a variable.

(2) An element of a search condition that expresses or implies a comparison operation.

preferred binary encoding

In OSI, the format in which an NSAP address or network entity title is passed in the network protocol.

preferred transport class

In OSI, a transport class that an application entity initially requests during association establishment. See also alternative transport class.

preloaded system

A system that is shipped with the licensed programs and program temporary fixes (PTFs) already installed on the disk.

preoperation exit program

A user-written program that is given control before operation of a system function.

prepared (PRP)

Pertaining to a logical unit of work state that indicates that the current logical unit of work is in doubt. The prepared state only occurs at nodes that are not a last agent.

prepared SQL statement

A named object that is the executable form of an SQL statement that was processed by the PREPARE statement.

prepare in progress (PIP)

The prepare in progress logical unit of work (LUW) state indicates that the current LUW is preparing its resources to commit. A failure during PIP state results in a rollback.

preprocessing exit program

An exit program that performs preprocessing when an operation is requested against an exit point. An example of a preprocessing exit program is the Preprocessing Exit Program for Add.

preprocessor

A routine that performs initial processing and translation of source code or data prior to compiling the source code or processing the data in another program such as an emulator.

preprocessor directive

In the C language, a statement that begins with the symbol # and is interpreted by the preprocessor during compilation.

preprocessor statement

In the C and C++ languages, a statement that begins with the symbol # and contains instructions that the preprocessor can interpret.

prerequisite fix

A temporary solution to or a bypass of a problem that is necessary to provide a complete solution to correct a problem. The system requires that you apply the prerequisite fix either before the PTF that needs it or with the PTF that needs it. See also corequisite fix, distribution requisite fix.

preruntime array

In RPG, an array that is loaded at the same time as the program, before the program actually begins to run. See also compile-time array, runtime array.

preruntime table

In RPG, a table that is loaded at the same time as the source program, before the program actually begins to run. See also runtime table.

presentation address

In OSI, an address that uniquely identifies an application entity. The presentation address consists of one or more NSAP addresses, a TSAP selector, an SSAP selector, and a PSAP selector.

presentation context

In OSI, the combination of an abstract syntax with a transfer syntax that specifies how to transfer and interpret defined data values between nodes.

presentation control

In Business Graphics Utility, an option that allows parts of a chart to be included or excluded when produced.

presentation controls

In Backup Recovery and Media Services, a system policy menu option for defining the presentation of days of the week, the beginning day of the week, and other special characters as they appear on Backup Recovery and Media Services displays.

presentation data value (PDV)

In OSI, a complete unit of information that is meaningful to an application entity.

presentation graphics routines (PGR)

A group of routines within the operating system that allows business charts to be defined and displayed procedurally through function routines. See also Graphical Data Display Manager.

presentation layer

In OSI architecture, the layer that provides services that enable functional units in the application layer to select a common syntax in order to define data and operations to be performed on the data.

presentation-layer protocol data unit (PPDU)

In OSI, a protocol data unit in the presentation layer.(I)

presentation-layer service access point (PSAP)

In OSI, a service access point in the presentation layer.

presentation-layer service data unit (PSDU)

In OSI, a unit of data transferred between the application layer and the presentation layer.

presentation service access point

The address of an OSI communications partner that identifies an application in a computer.

prestart job

A batch job that starts running before the remote program sends a program start request.

previous release

The last required release of the system (such as Release 1.0) prior to the current release (such as Release 2.0), including any modification levels (such as Release 1.0 Modification Level 1 or Modification Level 2) that were not required.

previous system

The system that sent the TELNET or pass-through request that brought the user to the current system.

PRI

See primary rate interface. See also basic rate interface.

primary axis

In the GDDM function, the axis used to plot data in a business chart. See also secondary axis.

primary disk pool

An independent disk pool that defines a collection of directories and libraries and may have other secondary disk pools associated with it. A primary disk pool also defines a database for itself and other disk pools that may be added in its disk pool group.

primary domain

The domain that is defined by the DNS domain database file on a primary name server.

primary file

(1) For certain types of join operations using Query, the first of all files that are joined in a query definition. The data from this file is used in every record formed by a join specification.

(2) In the DDS for a join logical file, the first physical file specified on the JFILE keyword. See also secondary file.

(3) In RPG, if specified, the first file from which RPG reads a record. In multifile processing, the primary file is used to determine whether the MR indicator is set on. See also full procedural file.

primary focal point

A network node that receives alerts from nodes that the user has defined in a sphere of control. See also default focal point, backup focal point.

primary folder

In System Manager, the folder into which the documentation of the corresponding development folder is stored if dynamic naming is not allowed for the option or if no override folder name is specified at install time.

primary group

A group profile whose authority to an object is stored with that object. Primary group authority may provide better performance than private group authority.

primary group authority

The authority that the primary group has to the object. See also owner authority, private authority, public authority.

primary key

In a relational database, a key that uniquely identifies one row of a database table. See also unique key, foreign key.

primary language

The national language installed on the system as the default language used to display and print information. The primary language is also used to service the system. See also secondary language.

primary library

In System Manager, for a code load, the library in which the code load is stored if dynamic naming is not allowed for the option or no override library names are specified at install time. For language loads, the library in which the language load is stored if the language load identification matches the primary language of the system and either dynamic naming is not allowed for the option or no override library names are specified at install time.

primary link

The optical connection between a local optical link card and a remote bus adapter card.

primary logical unit (PLU)

In SNA, the logical unit that contains the primary half-session for a particular logical unit-to-logical unit (LU-to-LU) session. See also secondary logical unit.

primary name server

A name server that always loads domain information from its own domain database file.

primary node

A cluster node that currently has the principle copy of a cluster resource. All replications of a resilient resource originate from the primary copy of the resource.

primary optical link

A connection between the system and an expansion unit. The hardware that creates this link is the local optical link card, the remote bus adapter, and the optical cables that connect the two.

primary partition

A logical partition that provides certain general functions on which all logical partitions are dependent. The primary partition is the only partition that is active in a system that has a single partition. All partition management functions are performed from this partition. If this partition is powered off or restarted, for example, the entire system is powered off or restarted.

primary rate interface (PRI)

An ISDN interface normally used by large sites, providing 30 (E1) or 23 (T1) B-channels of 64 kbits per second and one D-channel for signaling. This is often known as 30B+D or 23B+D. See also basic rate interface.

primary system

In a remote journal network, the System i system where the original database resides.

primary system console

A workstation that is attached to the first input/output processor that is capable of supporting workstations. If Operations Console has been configured, a personal computer (either at a local location or a remote location) becomes the primary system console.

primary system name

In SNADS, the system name of the highest logical unit in the network. See also secondary system name.

primary thread

See also secondary thread. See initial thread.

primary window

The window in which the main interaction between the user and an object takes place.

prime record key

In COBOL, a key whose contents uniquely identify a record within an indexed file.

primitive

A simple and fundamental data structure, API, algorithm, or system service that serves as a building block for more complex solutions, applications, or environments.

principal

An entity that can communicate securely with another entity. A principal is identified by its associated security context, which defines its access rights.

principal development library

In System Manager, a development library into which a load object (*PRDLOD) is created.

principal library

In System Manager, the library that contains the load object (*PRDLOD).

principal name

In the Kerberos protocol, the name by which the Kerberos principal is identified. The principal name usually consists of either a) a user name and a realm name or b) a service name, host name, and a realm name.

principal primary library

In System Manager, a primary library into which the objects that were created in the principal development library are stored when no overriding library name is specified at installation time.

print band

An interchangeable metal band that contains the print characters used by some printers.

print descriptor

An object used to manage printing that is created and maintained by the PrintManager™ program. Print descriptors describe where a print job is printed, how a print job is processed, and how output appears. The print descriptors contain capabilities and defaults of options used for printing. The system-recognized identifier for the object type is *PDG.

print descriptor group

An object used to store print descriptors so they can be managed effectively on a system. The system-recognized identifier for the object type is *PDG.

printer/display layout

A specification on which the user can design the format for a report either printed or displayed.

printer file

A device file that determines what attributes printed output will have. A particular printer may or may not support all of the attributes specified in a printer file.

printer ID

The identification code assigned to printers.

printer output

A file that holds output data that is waiting to be processed for printing.

printer session

A PC program that allows a personal printer to emulate a host system printer.

printer spooling

In CICS®, a facility that provides support for writing data to print spools. Only printed output is supported by CICS.

printer writer

A system program that writes spooled files to a printer.

print format utility (PFU)

In AFP Utilities, a utility that allows a user to print a database file member in various formats without writing any programs.

PrintManager

The collective name for a set of IBM programs or operating system functions that provide cross-system print management for an entire organization.

print option

A specification for printing a document.

printout format definition (PFD)

In AFP Utilities, a file member that contains information about the record layout, page layout, record selection, and database file name. A PFD is used to print the records of a database file member in various formats.

Print Services Facility™ (PSF)

(1) A feature of i5/OS that provides AFP system management and IPDS print management to IPDS printers that are connected to System i systems.

(2) An IBM licensed program that manages and controls the input data stream and output data stream required by supported IBM page printers.

print share

An output queue that is shared with PC clients on the network.

print text

An option that allows the user to specify a line of text at the bottom of a list.

priority queue

In SNADS, a queue that contains distribution queue entries for distributions with a service level of fast, status, or data high. When send times and queue depths are satisfied for both the priority and normal queues, the priority queue is serviced first. See also normal queue.

private authority

The authority specifically given to a user for an object that overrides any other authorities, such as the authority of a user's group profile or an authorization list. See also owner authority, primary group authority, public authority.

private branch exchange (PBX)

A switching system located on a customer's premises that consolidates the number of inside lines (extensions) into a smaller number of outside lines (trunks). Many PBXs also provide advanced voice and data communications features.

private key

In secure communication, an algorithmic pattern used to encrypt messages that only the corresponding public key can decrypt. The private key is also used to decrypt messages that were encrypted by the corresponding public key. The private key is kept on the user's system and is protected by a password. See also key, public key.

private management domain (PRMD)

In OSI X.400, a private company or noncommercial organization that handles a management domain.

private network

A network established and operated by a private organization or corporation for users within that organization or corporation. See also public network.

private storage pool

A storage pool containing a specified amount of storage that can be used by only one subsystem. See also shared storage pool.

privilege

In SQL, a capability given to a user by the processing of a GRANT statement.

PRM

See program resolution monitor.

PRMD

See private management domain.

probe

A type of message that determines if a message with certain characteristics can be delivered to a specific recipient. This type of message is treated like a user message by the message transfer agent (MTA), except that it is never delivered to the recipient.

problem analysis

The process of finding the cause of a problem. For example, a program error, device error, or user error.

problem isolation procedure (PIP)

Written information used by service representatives to repair IBM equipment. A PIP contains yes/no questions and procedures that direct the user to the failing part of the equipment.

problem log

A record of problems and of the status of the analysis of those problems.

problem management

In System Manager, the discipline that manages the detection, analysis, correction, and tracking of problems occurring in an information system environment.

problem management focal point

The management services responsible for the problem analysis and diagnosis for a sphere of control. An alert focal point is a subset of a problem management focal point.

procedural programming

In RPG, a programming technique in which the input and output operations are controlled by programmer-specified operation codes instead of by the program cycle.

procedure

(1) In the Integrated Language Environment® (ILE) model, a set of self-contained high-level language (HLL) statements that performs a particular task and returns to the caller. Individual languages have different names for this concept of a procedure. In C, a procedure is called a function.

(2) In query management, a query object that consists of a related set of query commands. A procedure allows an application to run multiple query commands through one call to the callable interface.

(3) In COBOL, one or more successive paragraphs or sections, within the Procedure Division, that direct the computer to perform some action or series of related actions.

procedure call

A call made to a procedure within a module in a bound program. See also program call.

Procedure Division

One of the four main parts of a COBOL program. The Procedure Division contains instructions for solving a problem. The Procedure Division may contain imperative statements, conditional statements, paragraphs, procedures and sections.

procedure language statement

In query management, a query command that is used in query procedures.

procedure name

In COBOL, a paragraph name or a section name in the Procedure Division.

procedure order profiling data

A portion of observability that is stored with a program that is produced by Integrated Language Environment (ILE) application profiling. The data lists the order in which the program's procedures were packaged and also indicates how the procedures should be packaged in the future if the program is rebuilt in some way. For example, if procedure A calls procedure B very often, then it is advantageous to package procedures A and B close together.

procedure pointer call

A high-level language call mechanism for specifying the address of a procedure to be called. The procedure pointer call provides a way to call a procedure dynamically. For example, by manipulating arrays or tables of procedure names or addresses, the application programmer can dynamically route a procedure call to different procedures. See also static procedure call.

process

(1) See job.

(2) An instance of a program running on a system and the resources that it uses.

(3) For Common Programming APIs ToolKit, the collection of all i5/OS jobs sharing an activation group.

(4) In System Manager, a combination of systems management applications that accomplishes one or more customer tasks or a part of a task. A process can contain other processes.

process access group (PAG)

A group of job-related objects that may be paged in and out of storage in a single operation when a job (process) enters or leaves a long wait.

process definition object

A WebSphere® MQ object that contains the definition of a WebSphere MQ application. For example, a queue manager uses the definition when it works with trigger messages.

processing

The action of performing operations and calculations on data.

processor

(1) A device for processing data from programmed instructions. It may be part of another unit.

(2) One or more integrated circuits that process coded instructions and perform a task.

Processor Active light

The light on the control panel that comes on when the processing unit is running.

product

In System Manager, a program or application that is identified as a product to the i5/OS operating system by a product identifier and a product definition.

product availability object

A system object used to store information about products and licensed programs. The system-recognized identifier is *PRDAVL.

product definition

In System Manager, an object that contains the information about a product. The object type is *PRDDFN. A product definition is identified as belonging to a product (PRDID) and a release (RLS). A given product and release can have only one product definition.

production

In OSI, a part of the formal notation used to specify ASN.1, in which allowed sequences of items are associated with a name that can be used to refer to those sequences in the definition of new sets of allowed sequences.

production copy

In cross-site mirroring, the independent disk pool to which all production operations are directed. All disk write operations are directed here first and are then replicated to the mirror copy of the independent disk pool. The production copy always has current data.

production library

A library containing objects needed for normal processing. See also test library.

product load

(1) The smallest logical collection of objects that can make a product option.

(2) In System Manager, an object that contains the control information about an option. The object type is *PRODLOD. A product load is identified by the product identifier (PRDID), release (RLS), option (OPTION), and load identifier (LODID) parameters.

product message file

In System Manager, a file containing one or more product descriptions.

product option

In System Manager, a group of one or more loads, one of which must be a code load.

product-sensitive programming interface (PSPI)

A special interface that is intended to be used only for a specialized task, such as diagnosis, modification, monitoring, repairing, tailoring, or tuning.

profile

Data that describes the characteristics of a user, group, program, device, or remote location.

profile handle

A value created by the system from the Get Profile Handle API that is used to identify a valid user ID and password. This value is used as input to switch the controlling user profile in a job to another user profile without changing the name of the job.

PROFS® bridge

See VM/MVS bridge.

program

(1) In the Integrated Language Environment (ILE) model, the executable object that results from binding modules together.

(2) A sequence of instructions that a computer can interpret and run without a user's intervention.

program automatic storage area (PASA)

A system object that contains call level information for each program on the call stack. The PASA can also contain space (allocated when the program object is called) for program variables.

program call

A call made to an ILE program or to an OPM program. See also procedure call.

Program Call Markup Language (PCML)

A tag language that is used to describe the input and output parameters for programs running on System i models. PCML is based on the Extensible Markup Language (XML). PCML files are used with the ProgramCallDocument class in the iSeries Toolbox for Java to automate parameter handling and calls of ILE programs from Java.

program control

A CICS facility that handles the flow of control among application programs.

program control table (PCT)

A CICS table defining the transactions that can be processed by the system. Each transaction is paired with the name of the program that CICS runs when the transaction is called.

program cycle

In RPG, the series of operations performed by the computer for each record read.

program-described data

Data contained in a file for which the fields in the records are described in the program that processes the file. See also externally described file.

program-described file

A file for which the fields in the records are described only in the programs that process the file. To the operating system, the record appears as a character string. See also externally described file.

program device

A symbolic device that a program uses instead of a real device (identified by the device name). When the program uses a program device, the system redirects the operation to the appropriate real device.

program device override

The attributes specified at run time that change the attributes of the program device.

program entry procedure (PEP)

A procedure provided by the compiler that is the entry point for an ILE program on a dynamic program call. See also user entry procedure.

program ID

A 1- to 8-character string entered from a finance device and associated with a server finance transaction program. Lists of valid program IDs and their associated application programs are maintained in program tables.

program identification entry

In COBOL, an entry in the PROGRAM-ID paragraph of the Identification Division that contains clauses that specify the program-name and assign selected program attributes to the program.

program initialization parameter (PIP)

The initial parameter value or values passed to a target program as input or used to set up the process environment.

program integrated information (PII)

Programs for the user interface such as menus, messages, and help panels.

program level

Pertaining to an operation that is performed for an entire program. See also command-level.

programmable workstation

A workstation that has some degree of processing capability and allows the user to change its functions.

programmed function key

On a workstation, a key that can perform various functions selected by the user or determined by an application program.

programmer subsystem

An IBM-supplied interactive subsystem used to code programs on a display station. The system object name is QPGMR.

programmer user profile

The system-supplied user profile that has the authority necessary for system and application programmers and the special authorities of save system authority and job control authority. Named QPGMR.

program message queue

An object used to hold messages that are sent between program calls of a routing step. The program message queue is part of the job message queue.

Programming Development Manager (PDM)

An application that is used in a 5250 emulator to query an i5/OS host and perform actions against objects. See also 5250 display.

programming interface for customers

The supported method through which customer programs request software services. The programming interface consists of a set of callable services provided with a product.

programming request for price quotation (PRPQ)

A customer request for a price quotation for a licensed program to be designed especially for a particular group of customers or an application. Documentation for the program is provided only to those customers who order the PRPQ. See also request for price quotation.

program name

A user-defined word that identifies a COBOL source program.

program object

One of two machine object classifications. It includes those objects used in programs that get their definition from an object definition table. Program objects are used as the parameter or values of machine instructions. See also system object.

program preparation

In DB2® UDB for iSeries, the process of producing a program. The process includes precompilation, compilation, and bind.

program profiling

A technique that is used to optimize a program.

program resolution monitor (PRM)

In the original program model (OPM), a program that translates the intermediate representation of a program into the machine language for use by the computer. The program resolution monitor is used by the programming language compilers to complete the translation of a source program into machine language instructions.

program static storage area (PSSA)

A system object that contains static variable data for programs on the call stack. The PSSA contains space for program variables that is activated when the program object is activated. The PSSA is contained in the process access group (PAG).

program table

A list of the i5/OS finance applications for use in an i5/OS finance job. Each table entry consists of a program ID and the program name and library associated with that ID. Program IDs received in data streams from finance devices are located in the program table to determine the i5/OS application that should be called.

program temporary fix (PTF)

For System i, System p™, and System z™ products, a fix that is tested by IBM and is made available to all customers. See also fix pack.

program variable

A named changeable value that can exist only within programs. Its value cannot be obtained or used when the program that contains it is no longer running.

promote

(1) In application development, to move a part up one level in the project hierarchy.

(2) In ILE, to convert an unhandled exception into a new exception with a different meaning. The new exception is passed on to the next exception handler.

prompt

A message or a displayed symbol that requests information or user action. The user must respond to allow the program to proceed.

Proof of Entitlement (POE)

A document that validates the licensed programs that a customer has purchased.

proportional spacing

The spacing of characters according to their relative width.

proposal

A proposal is a collection of protocols that the initiating and responding key servers use to establish a dynamic virtual private network (VPN) connection between two endpoints.

proposed abstract syntax list

In OSI, a list of abstract syntaxes that an application entity specifies as acceptable when initiating an association.

protected conversation

A type of conversation that supports the two-phase commit process for the synchronization of changes.

protected field

A field on a display in which a user cannot add, change, or delete data.

protected file

A file that cannot be changed by an override file command.

protected logical unit of work (protected LUW)

The logical unit of work that is used in a protected conversation.

protected logical unit of work identifier (protected LUWID)

The logical unit of work identifier that is used in a protected conversation.

protected LUW

See protected logical unit of work.

protected LUWID

See protected logical unit of work identifier.

protected password

In APPC, a string of bytes that is substituted for a user password. The protected password is sent instead of the user password and can be used to verify the identity of the user but only under specific and controlled circumstances. The LU type 6.2 architecture refers to the protected password as a password substitute.

protected resource

(1) A resource that is updated only in accordance with the two-phase commit process.

(2) A resource that is updated in a synchronized manner during resource recovery processing.

protected storage

(1) All auxiliary storage in an auxiliary storage pool (ASP) when mirrored protection is in effect.

(2) The part of the auxiliary storage pool (ASP) that is reserved for the creation of permanent objects, such as libraries and files, when checksum protection is in effect.

protection level

The degree to which secure network communications are protected.

protection setup

In Internet communications, a group of protection subdirectives that work together to define how the server should control access to the resources being protected.

protocol

(1) A set of rules controlling the communication and transfer of data between two or more devices or systems in a communication network.

(2) In OSI, a specification of the format and relative timing of information exchanged between peer entities within a layer.

Protocol 1 (P1)

The message transfer protocol used to relay X.400 messages between message transfer agents (MTAs).

Protocol 2 (P2)

The message protocol used between user agents to convey the syntax and structure of an X.400 message and to specify what a recipient user agent does with the message.

protocol converter

A general term for a device that changes one type of coded data to another type of coded data for processing.

protocol data unit (PDU)

(1) In OSI, a unit of data exchanged between peer entities.

(2) A unit of data exchanged between peer systems.

proxiable ticket

A ticket granting ticket (TGT) that allows you to get a ticket for a service with IP addresses other than those in the TGT. Unlike forwardable tickets, you cannot proxy a new TGT from your current TGT; you can only proxy service tickets. Forwardable tickets let you transfer your complete identity (TGT) to another machine, whereas proxiable tickets only let you transfer particular tickets. Proxiable tickets allow a service to perform a task on behalf of a principal. The service must be able to take on the identity of the principal for a particular purpose. A proxiable ticket tells the KDC that it can issue a new ticket to a different network address, based on the original ticket granting ticket. With proxiable tickets, a password is not required.

proxy gateway

A firewall that prevents users outside a private network from accessing computers within the private network.

proxy server

A server that receives requests intended for another server and that acts on the client's behalf (as the client's proxy) to obtain the requested service. A proxy server is often used when the client and the server are incompatible for direct connection. For example, the client is unable to meet the security authentication requirements of the server but should be permitted some services.

PRP

See prepared.

PRPQ

See programming request for price quotation. See also request for price quotation.

PSAP

See presentation-layer service access point.

PSAP selector

In OSI, an external identifier for a service access point at the Presentation Layer. The PSAP selector is part of a presentation address.

PSDN

See packet-switched data network.

PSDU

See presentation-layer service data unit.

pseudo-CL variable

In REXX, a variable used in CL commands, whose name conforms to the CL programming rules for variables but actually refers to a REXX variable. The name must begin with an ampersand, but it is stripped off when determining the name of the actual REXX variable that is to be used. Pseudo-CL variables must be valid REXX variable names and valid CL variable names.

pseudocode

A set of instructions that has a logical structure but does not follow the syntax of any particular programming language.

pseudorandom number

A number that is obtained by some defined arithmetic process, but is effectively a random number for the purpose for which it is required.

pseudo-text

In COBOL, a sequence of character-strings and/or separators bounded by, but not including, pseudo-text delimiters. Pseudo-text is used in the COPY REPLACING statement for replacing text strings.

pseudo-text delimiter

In COBOL, two equal signs (==) side by side used to define the beginning and end of pseudo-text.

PSF

See Print Services Facility.

PSH

See physical services header. See also enhanced logical link control, qualified logical link control.

PSPI

See product-sensitive programming interface.

PSSA

See program static storage area.

PSTN

See public switched telephone network.

PTF

See program temporary fix. See also fix pack.

PTF group

A single, orderable PTF (program temporary fix or simply, fix) that provides a logical set of PTFs for a specific function such as database or Java. PTF groups are dynamically updated when new PTFs for the same function become available.

PTF media

The diskette, tape, or CD-ROM on which the user receives program temporary fixes (PTFs).

pthread

A shortened name for the i5/OS threads API set that is based on a subset of the POSIX standard.

PTT

See Post Telephone and Telegraph Administration.

PU

See physical unit. See also control point.

Public Address Book

See Domino® directory.

public authority

The authority given to users who do not have any specific (private) authority to an object, who are not on the authorization list (if one is specified for the object), and whose group profile has no specific authority to the object. See also owner authority, primary group authority, private authority.

public data network (PDN)

(1) A network operated by a government or private organization to provide computer communications to the public, usually for a fee. With a PDN, a small organization can create a WAN without incurring the equipment costs of long-distance circuits.

(2) A communications common carrier network that provides data communications services over switched or nonswitched lines.

public interface

The names of procedures and data items, exported from an ILE service program, that can be accessed by Integrated Language Environment (ILE) programs or other service programs.

public key

In secure communication, an algorithmic pattern used to decrypt messages that were encrypted by the corresponding private key. A public key is also used to encrypt messages that can be decrypted only by the corresponding private key. Users broadcast their public keys to everyone with whom they must exchange encrypted messages. See also key, private key.

public key cryptography

A cryptography system that uses two keys: a public key known to everyone and a private or secret key known only to the recipient of the message. The public and private keys are related in such a way that only the public key can be used to encrypt messages and only the corresponding private key can be used to decrypt them.

public key infrastructure (PKI)

A system of digital certificates, certification authorities, and other registration authorities that verify and authenticate the validity of each party involved in an Internet transaction.

public network

Generically, a network operated by common carriers or telecommunications administrators for the provision of circuit-switched, packet-switched, and nonswitched lines to the public. See also private network.

public switched telephone network (PSTN)

A communications common carrier network that provides voice and data communications services over switched lines.

pull-down menu

In a character-based interface, a menu that emerges in a downward direction from a point or line at or near the top of the screen; for example, a menu that appears when the user selects a particular display element or points to a line in another menu by using a device such as a mouse.

purge

In Performance Tools, a job attribute that specifies whether a job is to be marked eligible to be moved out of main storage to auxiliary storage when entering a long wait or leaving the activity level.

push

To add an item to the top of a pushdown list. See also pop.

push button

In a window or dialog box, a rectangular control that, when clicked, immediately causes an action to be performed. Push buttons can be labeled with text, graphics, or both. The most familiar push buttons are OK and Cancel.

pushdown list

A list that is constructed and maintained so that the next data element to be retrieved is the most recently stored. See also last-in first-out.

PU type

See physical unit type.

PVC

See permanent virtual circuit.