$XABPRO

   The $XABPRO macro allocates and initializes a XABPRO. No value is
   returned for this assembly-time operation.

   Format

     $XABPRO  ACLBUF=ACL-buffer-address,

              ACLCTX=<ACL-context>,

              ACLSIZ=ACL-buffer-size,

              MTACC=magnetic-tape-accessibility,

              NXT=next-xab-address,

              PRO=<system, owner, group, world>,

              PROT_OPT=<PROPAGATE>,

              UIC=<group, member>