/sys$common/syshlp/helplib.hlb PASCAL, /USAGE[=(option[,...])] D=platform-specific  *Conan The Librarian (sorry for the slow response - running on an old VAX)

                                   D=/USAGE=(EMPTY,PACKED,UNSUP,UNINIT) (OpenVMS VAX)
                                   D=/USAGE=(EMPTY,PACKED,UNSUP,UNINIT,VOLATILE) (OpenVMS Alpha)
  /NOUSAGE

  Directs the compiler to perform compile-time checks indicated by
  the   chosen   options.   A  single  identifier  or  a  list  of
  identifiers enclosed in parentheses  may  follow  /USAGE;  these
  identifiers  are  options that tell the compiler which checks to
  perform.  The options are as follows:

     ALL
       Enables checking of all options.

     NONE
       Disables all /USAGE options.

     [NO]EMPTY_RECORDS
       Checks for fetching records with no fields. Such fields are
       usually created by the %DICTIONARY directive for unsupported data
       types.

     [NO]NONGRNACC
       Detects  code for which the compiler cannot generate requested
       granularity.

     [NO]PACKED_ACTUALS
       Checks for passing components of packed structures to VAR
       parameters.

     [NO]PERFORMANCE
       Checks for declarations and uses that will result in less than
       optimal performance.

     [NO]UNCERTAIN
       Checks for variables that may be uninitialized depending on
       program flow.

     [NO]UNINITIALIZED
       Checks for variables that are known to be uninitialized.

     [NO]UNSUPPORTED_CDD
       Checks for usage of CDD/Repository constructs that do not
       correspond to Compaq Pascal data types.

     [NO]UNUSED
       Checks for variables that are declared but never referenced.

     [NO]UNCALLABLE
       Checks for routines that are declared but never referenced.
       (OpenVMS Alpha only)

     [NO]VOLATILE
       Checks for accesses to volatile data that cannot be protected as
       atomic operations. (OpenVMS Alpha only)

  See the "Compaq Pascal Language Reference Supplement for OpenVMS
  Systems"  for  a  list  of  the  types of variables that are not
  checked for uninitialization.

  By  default  on  OpenVMS  VAX  systems,   /USAGE=(EMPTY_RECORDS,
  PACKED_ACTUALS,  UNSUPPORTED_CDD, UNINITIALIZED) is enabled.  By
  default  on  OpenVMS   Alpha   systems,   /USAGE=(EMPTY_RECORDS,
  NONGRNACC,   PACKED_ACTUALS,   UNSUPPORTED_CDD,   UNINITIALIZED,
  VOLATILE) is enabled.  /USAGE without options is  equivalent  to
  /USAGE   =ALL.    The   negation   /NOUSAGE   is  equivalent  to
  /USAGE=NONE.