  globalvalue, globalref, extern? (C syntax) 
 The Question is:
 
Is the use of external storage classes and global storage classes
interchangeable.
We currently use several 'globalvalue' declarations to link to some RDB
constants but 'globalvalue' is an extension to the ANSI standard - in order
to be fully ANSI compliant can 'extern' be used in place of 'globalvalue'.
 
 The Answer is:
 
  globalvalue and globalref are VAX C extensions.  They can be freely
  mixed with extern variables and declarations when DEC C is requested
  to allow VAX C extensions during the compilation.
 
  Please see the DEC C documentation around the use of /EXTERN_MODEL
  and /SHARE_GLOBALS appropriate for your application.
 
  Depending on what you are using with Rdb, you may need to use the
  PSECT_ATTR item (via a LINKER options file) to control the specific
  attributes of Rdb-related program sections.
 
