I could not find discrete codes for my JVC dcd player or Marantz 5200 reciever, but I found a way to mimic them that works every time so far (one days worth of testing :)

It is fairly simple, and can probably be used for other device types as well, and I would imagine it has been mentioned here before as it is not that much of a breakthrough, but I thought I would share since I hadn't read anything on it.

Here is how it works. On the JVC dvd player the play button will always turn on the dvd player, but it obviously won't turn it off. On my Marantz reciever, the VCR, TV function buttons turn on the reciever, but obviously just switch if it is on. So what I do is to for System Off -- program a macro. First hit the play button for dvd (turns on if off, play if on), then hit vcr function button (turn reciever on if off and switches to vcr, or just switches to vcr if on), then hit the tv off discrete (sony), then hit the power for the dvd player (was on or had been turned on by macro), then hit power for reciever (was on or turned on by macro). Now everything is off.

This will work for any device I guess that has some button that will turn on the device but won't turn it off.

Hope you find that helpful.