Since we really only have a list of instructions without any descriptions we have to scour the myriad of P2 posts for information and then we have to filter out what is current as well. I've been adding a few bits of information to a document which has the instruction set and any other information such as memory maps etc that are necessary for writing assembly code for the P2.
Anyone can edit this P2 2015 Assembly Instruction Set
edit: here is a link for the published (view only) document version
So even just comments will help and any pearls of wisdom gleaned from the forum. Later on this can all be reformatted nice and neatly but otherwise it would be a good repository and reference.