In chapter 4 of the Official Samba 3.2.x HOWTO and Reference Guide, available at http://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/samba-pdc.html, in the section titled, "Preparing for Domain Control", there is a link with link text content, "domain logons".
That link is pointing to the URL, http://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/smb.conf.5.html#DOMAINLOGONS
No page is available at http://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/smb.conf.5.html
I guess that maybe it's supposed to reference chapter 5 of the containing document. I wouldn't know for sure, though. It looks like it would probably be a reference that could use an update, just wanted to bring it to attention here -- those docs aren't small works, as I do quite realize.
These docs are not maintained.