You can modify the schema by creating new object classes or attributes, or by deleting object classes and attributes. Deleting object classes or attributes is not advisable; some directory entries might use the existing definitions.
Caution - There is no automatic check to ensure that schema modifications do not invalidate entries. Therefore, to minimize the risk of entries becoming invalid, restrict your changes to addition or modification of object classes or attributes.
To create, add, or modify new attributes, use the commands ldapadd or ldapmodify, as described in Chapter 2, "Commands Reference," in the sections "ldapadd" and "ldapmodify."