I am under the impression that these are still on-topic as per Krazer's reply to my comment in his answer which is the accepted policy to ID Requests
@Memor-X Music identification is series specific, so it's not an id-req. Questions about doujinshi should be acceptable. However identifying a doujinshi of a specific series is an id-req and should not include a series tag as there really is no direct connection. However if you wish would like to ask about finding a doujinshi a specific author did on a specific series, then you can use the author name and the series name as tags. This makes identifying the title more specific and answerable, as opposed to grasping for straws in the dark like we currently do for id-reqs.
Remember that Music Identification is generally a hell of a lot easier because we will know the anime and the asker is expected to give us when about the music plays in the form of describing the scene of a timed youtube link and most of the time the answer lies in the Soundtracks.
Scene identification for the most part i would be ok with it since you can get questions like asking when flashback originally occurred because with animation, to save money scenes are reused (ie. in Bleach when Karin thinks back to when she was at the graveyard and was attacked by a Hollow), the origin scene to a meme (ie. the pregnancy test meme), etc.
ofcause these kinds of questions, just as Krazer's comment says it's series specific and more or less fall under the lines of iding characters/objects within a series.