Hey, silly question... what's APLD do on a VCR?!? On an audio cassette deck it's a music search system. I.E. if you activate APLD and hit rewind/ff, it will find the next blank spot between songs and start playing there. It was a common feature of Sharp's tape decks (& boomboxes!) of the late 70s through 80s. I once saw a cool APLD sticker on a tape deck, "The Sharp Eye is quicker than the hand."
Kinda like this ad...