gentoo's package.provided equivalent?

[Sid --]

The FreeBSD Forums will be the place to search and ask for additional help to do that.

>> Sometimes i need to build specific version of some library from source,
>> not from ports. How can I tell port system about it. There was no problem
>> with old pkg_, because I was able just to put dummy directory into
>> /var/db/pkg and port system knows it is installed (although maybe that was
>> ugly hack). But what I can do with pkgng now? For example, Gentoo linux
>> has /etc/portage/profile/package.provided file for such a situation. Is
>> there some equivalent?

FreeBSD does have pkgng, but I'm not sure if it's the same thing.
Some versions of packages can be chosen, but I believe that ports versions can be chosen too.
The "Porter's Handbook", and "FreeBSD Handbook" may also provide assistance.