Ok then I prefer this way. The most important thing is that I can remove the package:
. /usr/share/univention-lib/ldap.sh
ucs_registerLDAPExtension --schema opsi.schema --packagename opsi4ucs-ldap-schema --packageversion 4.0.1.8-1
I assume I can do the same for univention-legacy-kolab-schema?
. /usr/share/univention-lib/ldap.sh
ucs_registerLDAPExtension --schema /usr/share/univention-ldap/schema/legacy/kolab2.schema
--packagename univention-legacy-kolab-schema --packageversion 2.0.1-1.21.201111081525
ucs_registerLDAPExtension --schema /usr/share/univention-ldap/schema/legacy/univention-kolab2.schema
--packagename univention-legacy-kolab-schema --packageversion 2.0.1-1.21.201111081525
ucs_registerLDAPExtension --schema /usr/share/univention-ldap/schema/legacy/kolab-legacy.schema
--packagename univention-legacy-kolab-schema --packageversion 2.0.1-1.21.201111081525
ucs_registerLDAPExtension --schema /usr/share/univention-ldap/schema/legacy/rfc2739.schema
--packagename univention-legacy-kolab-schema --packageversion 2.0.1-1.21.201111081525