[Mediawiki-l] shared user database

[Una]

Hi.  http://www.mediawiki.org/wiki/Manual:Preventing_access mentions a
method of rudimentary access control involving two mediawiki wikis, one
public, one private, with a shared user database.  That sounds like
what I want to migrate a pair of existing e-mail discussion groups onto
wikis.  The groups share a lot of content and members, but one group is
public and the other is (nominally) private.

The difficulty is, "shared user database" is a redlink.  Could anyone
here help me fill in the details?

Could this be the correct link:
http://www.mediawiki.org/wiki/Manual:%24wgSharedDB

Thanks,

	Una