*X's equal round number. If XXXX = 7FFF and xxxx = FFFF, visual round number is 0x7FFFFFFF (2147483647).
**To use properly, start the game and finish round one. Then Press the plus button once the round number starts flashing. After the round updates to the round of your choice, press the Plus button again. There will likely be temporary frame drops anytime a round changes. Otherwise, lag probably won't be present. So as long as the plus button is pressed the second time, the game will not crash whenever you leave zombies. Otherwise, the game will likely crash.
***Appears to only affect the visuals controlling the round. The actual round is seems to be permanently set to 1 and this can be seen by being able to knife zombies once to kill them. When you die, it will say you've only survived one round.
****I have no idea if other players are able to see this. I only tried this in single player.