Most of the OpenLDAP overlays are now compiled as dynamic modules in our
packages. If you want to use any of these in your setup make sure to put
the correct "olcModuleLoad" or "moduleload" statements in your configuration.
For details please see the slapd-config(5) and slapd.conf(5) manpages
(depending on which config mechanism you use).

For a list of the list of included dynamic modules see the
"/usr/lib/openldap/modules/" directory.

For convenience and backwards compatibility some overlays are are still
compiled statically into the slapd binary. To see which overlays that are
call "/usr/lib/openldap/slapd -VVV". Currently these are:

syncprov (the provider part of syncrepl replication)
ppolicy (a LDAP Password Policy implementation)

Documentations for the overlays can be found in the respective man pages
(named "slapo-<overlay-name>") or the OpenLDAP Administration Guide which
is part of the "openldap2-doc" package.