$RAB

   The $RAB macro allocates storage for a RAB and initializes
   certain RAB fields with defaults and user-specified values.
   You cannot use this macro within a sequence of executable
   instructions. No value is returned for this assembly-time
   operation.

   Format

     $RAB  BKT=bucket-code-number,

           CTX=user-context-value,

           FAB=fab-address,

           KBF=key-buffer-address,

           KRF=key-of-reference-number,

           KSZ=key-size,

           MBC=multiblock-count-number,

           MBF=multibuffer-count-number,

           PBF=prompt-buffer-address,

           PSZ=prompt-buffer-size,

           RAC={KEY|RFA|SEQ},

           RBF=record-buffer-address,

           RHB=record-header-buffer-address,

           ROP=<ASY BIO CCO CDK CVT EOF EQNXT ETO FDL KGE KGT LIM

           LOA LOC NLK NXR NXT PMT PTA RAH REA REV RLK RNE RNF RRL

           TMO TPT UIF ULK WAT WBH>,

           ROP_2=<NQL NODLCKWT NODLCKBLK>,

           RSZ=record-size,

           TMO=time-out-number-of-seconds,

           UBF=user-record-buffer-address,

           USZ=user-record-buffer-size,

           XAB=xab-address