You can specify the location of the data file using the logical name CXX$DEMANGLER_DB. For example, if the data file is in your login directory and is named MYCXXDB.DAT, you would define the CXX$DEMANGLER_DB logical name as follows: $ DEFINE CXX$DEMANGLER_DB SYS$LOGIN:MYCXXDB.DAT If you do not define the CXX$DEMANGLER_DB logical name, CXXDEMANGLE looks for the data file in the repositories specified by the /REPOSITORY qualifier. If you do not specify the /REPOSITORY qualifier, CXXDEMANGLE looks for the data file in the sys$disk:[.cxx_repository] directory.