Hello people: I need some help, hope my bad english let me explain myself:

There was a hotkey or command I used, to do it but I can't remember it:

In the edge of a model I was able to select a vert, then, using this command create other vert over this, then moving one of this vert to a side and the new one to the other side, creating an inverted (putside down)  "V" shapped cut at the edge of the model. In the picture I show the vert where I want to do the cut.

Thanks in advance.

I'm not sure what you're asking, but this sounds vaguely like the Loop Cut (shorctut "K").

It is better to do one thing well, than to do many things and excel at nothing.

Thanks for the answer DramaKing but it is not the  loop cut.

OK, I've found it is the "V" shortcuot LOL the "Rip command"

yes easy to remember as its the form it makes lol.

for some free stuff i made
and for almost daily fotos

See, you learn something everyday. That feature is completely new to me.

It is better to do one thing well, than to do many things and excel at nothing.

And sure very useful to verts accidentally joined after a remdoubles.