How to read dotted decimal diagrams

In dotted decimal format, each syntax element is written on a separate line. If two or more syntax elements are always present together (or always absent together), they can appear on the same line, as they can be considered as a single compound syntax element.

Each line starts with a dotted decimal number, for example

3 or 3.1 or 3.1.1. To hear these numbers correctly, make sure that your screen reader is set to read out punctuation. All the syntax elements that have the same dotted decimal number (for example, all the syntax elements that have the number

3.1) are mutually exclusive alternatives. For example, if you hear the lines

3.1 USERID, 3.1 SYSTEMID, you know that your syntax can include either USERID or SYSTEMID, but not both.

The dotted decimal numbering level denotes the level of nesting. For example, if a syntax element with the dotted decimal number

3 is followed by a series of syntax elements with the dotted decimal number

3.1, all the syntax elements numbered

3.1 are subordinate to the syntax element numbered

3.

Characters such as commas that are used to separate a string of syntax elements, are shown in the syntax just before the items they separate. They might appear on the same line as each item, or on a separate line with the same dotted decimal number as the relevant items. The line might also show another symbol giving information about the syntax elements; all these symbols are explained below. For example, the lines

5.1* ,, 5.1 LASTRUN, 5.1 DELETE mean that if you use more than one of the syntax elements

LASTRUN and DELETE, they must be separated by a comma. If no separator is given, assume that you use a blank to separate each syntax element.

If a syntax element is preceded by the

% symbol, this indicates a reference that is defined elsewhere. The string following the

% is the name of a syntax fragment, rather than a literal. For example, the line

2.1 %OP1 means that at this point, you should refer to the separate syntax fragment

OP1. OP1, in the syntax from which this example was taken, gave a list of further options.

Certain words and symbols are used next to the dotted decimal numbers to add information about the syntax elements. Occasionally, these words and symbols might occur at the beginning of the element itself. For ease of identification, if the word or symbol is a part of the syntax element, it is preceded by the escape character, which is a \ (backslash). For example, the

* symbol can be used next to a dotted decimal number to mean that this syntax element can be repeated. If a syntax element actually starts with the

* symbol, for example a syntax element

* FILE with the dotted decimal number 3, it is given in the format

3 \* FILE. If the format is 3* FILE, this means that there is a syntax element FILE, which can be repeated. If the format was

3* \* FILE, this means that there is a syntax element

* FILE, which can be repeated.

The words and symbols used next to the dotted decimal numbers are as follows: