VMS Help SHOW, LOGICAL, Parameter  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 logical-name[:][,...]

    Specifies one or more logical names whose translations you want
    to display. The asterisk (*) and the percent sign (%) wildcard
    characters are allowed; however, if a wildcard character is used,
    iterative translation is not done.

    The logical name is translated iteratively up to a number
    of times determined by the system (from 9 to 11). That is,
    translations are examined to see if they are also logical names.