Maintaining Consistent Schema54 Netscape Directory Server Deployment Guide • August 2002The following sections describe in detail how to maintain consistency within yourschema.Schema CheckingSchema checking ensures that all new or modified directory entries conform to theschema rules. When the rules are violated, the directory rejects the requestedchange.By default, the directory enables schema checking. We do not recommend turningit off. For information on turning schema checking on and off, see the NetscapeDirectory Server Administrator’s Guide.With schema checking on, you must be attentive to required and allowed attributesas defined by the object classes. Object class definitions usually contain at least onerequired attribute, and one or more optional attributes. Optional attributes areattributes that you are allowed, but not required, to add to the directory entry. Ifyou attempt to add an attribute to an entry that is neither required nor allowedaccording to the entry’s object class definition, then Directory Server returns anobject class violation message.For example, if you define an entry to use the organizationalPerson object class,then the commonName (cn) and surname (sn) attributes are required for the entry(you must specify values for these attributes when you create the entry). Inaddition, there is a fairly long list of attributes that you can optionally use on theentry. This list includes such descriptive attributes as telephoneNumber, uid,streetAddress, and userPassword.Selecting Consistent Data FormatsLDAP schema allow you to place any data that you want on any attribute value.However, it is important to store data consistently in your directory tree byselecting a format appropriate for your LDAP client applications and directoryusers.NOTE Schema checking checks only that the proper attributes are present.It does not verify whether attribute values are in the correct syntaxfor the attribute.