The $NAM_STORE macro moves user-specified values into fields of
    the specified NAM block. The expanded $NAM_STORE code executes
    at run time on a previously initialized (allocated) NAM block,
    in contrast to the $NAM macro, which initializes a NAM block at
    assembly time. The $NAM_STORE macro must reside in a code program
    section.
    Format
      $NAM_STORE  NAM=nam-address,
                  DID=#directory-identification,
                  DVI=#device-identification,
                  ESA=expanded-string-address,
                  ESS=#expanded-string-size,
                  FID=#file-identification,
                  NOP=<NOCONCEAL NO_SHORT_UPCASE PWD SRCHXABS
                  SYNCHK>,
                  RLF=related-file-nam-block-address,
                  RSA=resultant-string-address,
                  RSS=#resultant-string-size