Library /sys$common/syshlp/uafhelp.hlb ADD, /IDENTIFIER, Parameter  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 id-name

    Specifies the name of the identifier to be added to the
    rights database. If you omit the name, you must specify the
    /USER qualifier. The identifier name is a string of 1 to 31
    alphanumeric characters. The name can contain underscores and
    dollar signs. It must contain at least one nonnumeric character.