ConnTag (MQBYTE128)

ConnTag is a tag that the queue manager associates with the resources that are affected by the application during this connection. Each application or application instance must use a different value for the tag, so that the queue manager can correctly serialize access to the affected resources. This field is an input field, and its initial value is MQCT_NONE.

See the descriptions of the MQCNO_*_CONN_TAG_* options for further details about values to be used by different applications. The tag ceases to be valid when the application terminates or issues the MQDISC call.

Note: Connection tag values beginning with MQ in upper, lower, or mixed case in either ASCII or EBCDIC are reserved for use by IBM® products. Do not use connection tag values beginning with these letters. Use the following special value if you require no tag:

MQCT_NONE: The value is binary zero for the length of the field.
For the C programming language, the constant MQCT_NONE_ARRAY is also defined; this constant has the same value as MQCT_NONE, but is an array of characters instead of a string.

This field is used when connecting to a z/OS® queue manager. In other environments, specify the value MQCT_NONE.

The length of this field is given by MQ_CONN_TAG_LENGTH. This field is ignored if Version is less than MQCNO_VERSION_3.