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

    CLISYMTBL sets the size of the command interpreter symbol table,
    which controls the number of DCL or MCR symbols that can be
    created.

    CLISYMTBL is a DYNAMIC parameter.