Assigning tests in memtest86?

I once knew how to skip some tests and assign certain number tests to run but I forgot. The memory is the second thing to go and I can't remember what the first is..

I used to be able to like run 4,6,7,8 tests, skipping some. It doesn't seem to work that way now.

Anyone have any clues?

Maybe this ought to be in the "memory" board?