Major Description
When using Novell's JLDAP client library (distributed with OpenLDAP), if you try to modify an entity by adding a value to an attribute that already has one value, the new value overwrites the old one instead of being added. Here's the code I use to add a new member to a group:
LDAPAttribute member = new LDAPAttribute("uniqueMember", dn);
LDAPModification mod = new LDAPModification(LDAPModification.ADD, member);
String groupDN = "cn=students,ou=groups,ouu=system";
lc.modify(groupDN, mod);
Apparently, specifying LDAPModification.ADD works as if LDAPModification.REPLACE had been specified.