mIRC uses Windows Media Player to play audio files with /splay and retrieve information about them with $sound(). So mIRC does support OGG files but you need the
relevant OGG codecs for WMP for it to work.
Because WMP auto-identifies the file type /splay's switches are no longer relevant. AFAIK they're just a throwback to when mIRC used internal routines for audio playback, which is why there's no switch for OGG files.
