Directory Server stores all directory server schema in the special cn=schema entry. This entry contains information on every object class and attribute defined for your directory server.
You can examine the contents of this entry as follows:
ldapsearch -h myServer -p 5201 -D cn=admin,cn=Administrators,cn=config -b "cn=schema" -s base "(objectclass=*)"
For strict compliance, the location of the schema subentry for a given entry is specified by the subschemaSubentry operational attribute. In this version of Directory Server, the value of this attribute is always cn=schema.