slam legality?

Hey guys,

I love the slam but do wonder about the following rule:

(illegal moves):
"Spiking an opponent to the canvas on his or her head or neck"

can anyone shed some light on how/when that's enforced? Does it have to be a complete vertical spike to be illegal or what?

Thanks Oboe.

Oboe -

I believe it is during a submission attempt, that is void. Not 100%, but i seem to remember it happening in another fight and that was explained

this. had he let go he could attempt to better place himself before the fall or even defend Phone Post 3.0