/sys$common/syshlp/helplib.hlb CC, Language topics, Storage Class Modifiers, noshare  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Noshare variables are assigned the PSECT attribute NOSHR.  Noshare
  variables may not be shared between processes.  This modifier is
  used when linking variables that are not to be shared within a
  shareable image.  You can use the noshare modifier with the
  storage-class keywords static, [extern], globaldef, and
  globaldef{"name"}.