AUTHMODULES in the pop3d

Project:Linux server
Component:Documentation
Category:bug report
Priority:normal
Assigned:Unassigned
Status:active
Project wiki:server
Related pages:#310: Courier
Description

http://www.courier-mta.org/FAQ.html#pop3run
In the above FAQ, there is mention of the "AUTHMODULES in the pop3d configuration file".

However, the said configuration file (ubuntu 12.04) does not contain this variable. The official web site / the courier man pages do not seem to have any documentation on how to edit this file and which parameters are available.

So, is there an AUTHMODULES configuration parameter for /etc/courier/pop3d ? If so: how to set it (what values)?
Where is this documented? (I searched but didn't find it).