In response to the results of the poll posted by Bloody Bosmer (located here), the Stronghold Directory is now its own subforum. There are now multiple labels you can apply to your threads, including one to indicate that the stronghold location is an OOC location. To apply more than one label to a thread, just select a second one (or a third/fourth/whatever) after you pick your first.

While viewing the forum, you can click on any of the labels to list ONLY the threads with those labels, so this should help you find what you're looking for a little faster.

There's also a subforum for stronghold discussion if you want to discuss something related to strongholds without posting your own listing.