Old code conversion

If you are converting existing messages, there are a few things you may see:

MCSFLAG=RESP
This keyword might be used instead of DESC=5 to indicate a command response. This is supported, but DESC=5 is preferred, and the WTO should be changed if convenient.

Descriptor codes can be changed by the installation's message exits, but MCSFLAGs cannot. For maximum flexibility for the customer, DESC=5 is preferred.
MCSFLAG= REG0 or QREG0
Old code might have the "register zero interface" (REG0 or QREG0). If these keywords are specified, the console ID is placed in the low-order byte of register zero before the WTO is issued.

Only a 1-byte console ID can be specified this way, so this code must be converted to use CONSID=.
Note:
1. As of V1R8, REG0 and QREG0 are no longer supported because of the removal of 1-byte console IDs.
2. The high-order 3 bytes of register zero are assumed to be a CONNECT ID, if this is a multiline message.
(Note: ).
Multiple messages
You may be issuing several messages (instead of one multiline) in response to a command. This should not be changed. Changing the messages in this way would be a serious incompatibility for any automation programs which were analyzing the messages.

"New" messages should be designed as a single multiline response, if possible.