Application programs request LU 6.2 services from the VTAM® program with the APPCCMD macroinstruction. The APPCCMD macroinstruction has many variations, most of which are designated with the CONTROL and QUALIFY keywords. Application programs use the APPCCMD macroinstruction to request both conversation and control operator verb functions.

Application programs can use VTAM LU 6.2 support with this macroinstruction and still issue other VTAM macroinstructions on non-LU 6.2 sessions.

The CONTROL keyword is the highest level qualifier on the APPCCMD macroinstruction and is required on the APPCCMD macroinstruction. The QUALIFY keyword handles additional variations of the APPCCMD macroinstruction and can be omitted if the RPL field for the QUALIFY value is set properly. For example, a series of requests to send data might require that an APPCCMD macroinstruction be issued several times, using the same RPL. The QUALIFY keyword can be omitted after the first SEND macroinstruction if it does not need to be changed.