What does CripplePlayer function do?

There is a Jass function, which looks like this:

native CripplePlayer takes player whichPlayer, force toWhichPlayers, boolean flag returns nothing

What does it do?

i think it has something to do with handicap on players. not sure tho.

In blizzard.j they use it when defeating players it seems

I think it reveals all your units to the enemy (like when you lose your base in melee)