Troy Knabe wrote:

We have a custom schema and we would like to require that all entries in ou=Group have that objectClass in order to be added. Can someone point me in the direction that I should be looking?

Usually requirements like this are handled by X.500 DIT Structure Rules but we don't yet support them in OpenLDAP. Instead, use a recent 2.4 release and look at AddContentACLs - only give write permission for Adds if the correct value is present in the objectclass attribute.