My guess: He wants that option in the anime search, in order to find animes which have episodes which have files with an audio track in language x and subtitles in language y.
And IMO, that'd be rather useless - unless you happen to have problems with understanding English subs. ^_^;
The same Guest wrote:I suppose it may be easy enough to implement this search
actually not at all.
the way the data is currently stored it is impossible to run that kind of search without killing the server.
some heavy caching would be required to make such searches possible and to be frank, i don't think it's worth the trouble.
Perhaps this could be added as feature request for the anidb client?
Searching by language using the local database of the client should not stress the server