Topping during flowering?

Isn't topping where you cut off the top of the stem so two will grow instead of one? When should I do this?

Definitely during vegetative - leave the plant alone once flowering starts. I think most growers agree after the fourth node appears, you can safely start topping.

Here's a pre and post topping of a 22 day old plant using the FIM (Fuck, I Missed) technique (the cut is higher than the normal topping)

great! thanks