VTAM® issues this message in response to a VARY ACT or VARY LOGON command. command failed for nodename because an unacceptable operand was entered.

If operand is a controlling LU, a controlling LU name was specified on the LOGON operand of a VARY ACT command for an application. Controlling LUs are only valid for logical units.

If a network-qualified name was entered on the ID operand of the command, VTAM issues nodename in the form netid.name.

If a network-qualified name was entered on the LOGON operand of the command, VTAM issues operand in the form netid.name.