I guess this is kind of an FAQ, but I could not find an explanation so
far. If it is an FAQ, maybe someone give me just a pointer to the right
information.
There are several cases where multiple names are defined for a single
OID, e.g. core.schema defines the names "street" and "streetAddress" both
for 2.5.4.9. The Administration Guide says that when attributes are sent
they are labeled with the first name. However, the other names are also
valid in requests. Now the problem is that some LDAP clients send names
in their requests that are known to the LDAP server as "secondary" names,
resulting in responses with other names than the ones in the request.
This results in clients not being able to process the response correctly,
although the requested data is available and even sent back to the client.
Examples are Mozilla Thunderbird and Apple Addressbook which use
different (but only one) names for OID 2.5.4.9 and others.
My personal impression (though I'm new to LDAP, but have quite some
experience with SNMP/SMI, which is also heavily based on ASN.1) is that
LDAP's design is broken in that it does send non-unique labels instead of
unique (and more compact) OIDs in the protocol. But maybe, I'm just
missing a way how to handle the problem correctly.