/sys$common/syshlp/helplib.hlb CC, /REPOSITORY  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Specifies a repository for the compiler to store shortened external
  name information.  When /NAMES=SHORTENED is specified, the compiler
  stores to the repository any external names that were shortened.
  The demangler utility can then be used to map the shortened names
  back to the names used in the original C program.

  By default, the qualifier is not active unless /NAMES=SHORTENED has
  been specified, in which case the default is
  /REPOSITORY=[.CXX_REPOSITORY].

  Note that the default name of the repository is the same as that
  used by the Compaq C++ compiler for decoding mangled names.  This
  is intentional.  A C++ mangled name cannot match a shortened name,
  so a single repository can be used by both the Compaq C and Compaq
  C++ compilers.