I believe this data type needs to be re-defined in the LDAPBis work, and
I believe there needs to be a more formal way of extending it with
"special" values.
Currently (in both RFC 2251, and LDAPBis work), this data type does not
allow the string "*" (or the proposed "+" for that matter). Both
specifications restrict it to a list of attribute descriptions. An
attribute description must either be a numeric oid, or begin with a
alpha. Yet both have "special wording" like: "There are two special
values which may be used: an empty list with no attributes, and the
attribute description string "*". Both of these signify that all user
attributes are to be returned. (The "*" allows the client to request all
user attributes in addition to any specified operational attributes).".
Another proposal furthers this and allows "+" to indicate that all
operational attributes are to be returned, and other proposals for other
special strings are in the works.