VMS Help CMS, SHOW, HISTORY, Command Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 object-expression

    Specifies an object about which history information is to be
    displayed. The object expression can be one or more class names,
    element names, group names, a wildcard expression, or a list of
    any of these, separated by commas. If you do not specify an object
    expression, CMS lists all classes, elements, and groups in the
    library.