Library /sys$common/syshlp/pca$help.hlb DEFINE, /COMMAND, Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 symbol-name

    Specifies the symbol name that you want associated with a list
    of PCA commands. The symbol name can be up to 255 characters long
    and may include letters, digits, underscores, and dollar signs.
    It cannot start with a digit. If symbol-name is already defined,
    the new definition replaces the old definition.

 command-string

    Specifies the string of PCA commands to associate with the symbol
    name. The command string must be enclosed in quotation marks and
    consist of the first part of a PCA command, a whole command, or a
    list of commands separated by semicolons