Communications Suite servers support the following schema choices:
Sun LDAP Schema 2 native mode
Corresponds to Directory Preparation Tool schema version choice 2. This is the default for a fresh installation.
Corresponds to the Directory Preparation Tool schema version choice 1.
Sun LDAP Schema 2 compatibility mode
Corresponds to Directory Preparation Tool schema version choice 1.5.
If you are still trying to decide which schema to use, for further explanation, see Understanding Schema Choices in Sun Java Communications Suite 5 Deployment Planning Guide, and the Sun Java System Communications Services 6 2005Q4 Schema Migration Guide.