As with single-session partners, special considerations apply to the SNASVCMG mode name group used by VTAM® for control functions. The application program should not use SNASVCMG sessions for conversations. SNASVCMG should be specified by the application program only for control operator functions or other transaction programs required to use this mode name. The only valid session limits for SNASVCMG are two sessions (with each partner assured one contention-winner session) or limits of 0. SNASVCMG cannot be specified as a mode name on a CNOS request for a single-session partner or on an APPCCMD CONTROL=OPRCNTL, QUALIFY=DEFINE macroinstruction.