Accorrding to the documentation in Next Generation Schema/SearchServerXML, I should be able to query annotation this way:

Example: http://localhost:8080/ws/2/annotation/?query=mbid:bdb24cb5-404b-4f60-bba4-7b730325ae47

replacing http://localhost:8080 with http://musicbrainz.org, this is the resulting url:

http://musicbrainz.org/ws/2/annotation/?query=mbid:bdb24cb5-404b-4f60-bba4-7b730325ae47.

If you try to hit it, you'll receive the "page not found" error.

Tryed to use "entity". "id" or "entityId" instead of "mbid", but got the same result.

http://musicbrainz.org/ws/2/annotation/?query=entity:bdb24cb5-404b-4f60-bba4-7b730325ae47.

http://musicbrainz.org/ws/2/annotation/?query=id:bdb24cb5-404b-4f60-bba4-7b730325ae47.

http://musicbrainz.org/ws/2/annotation/?query=entityId:bdb24cb5-404b-4f60-bba4-7b730325ae47.

thanks in advance.

Marco