/sys$common/syshlp/helplib.hlb CMS, INSERT, GENERATION, Qualifiers, /GENERATION[=generation-expression]  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Specifies a particular generation of the element that is to be
    inserted into the class. If you omit /GENERATION, the INSERT
    command uses the latest generation on the main line of descent.