The same problem applies to S1 style ids.
As an example, what led to this post was a desire to embed my LJ in a website. I found the basic topic without too much difficulty, but then, when I wanted to find out what the S2ID for my style was, I had to hunt for twenty minutes among multiple topics before I found it in an unexpected place (and it's not listed under the Manage > Styles page). (excerpt from comment)
User had HTML Frames/iFrames as an embedding method (http://www.livejournal.com/support/see_request.bml?id=601478), so some of this is howto_userdoc material too. Since I believe many of those people watch this comm too, I'm posting here first rather than cross-posting.