Vegitative Growth

I'm not a complete newbie, I've got a few really good grows under my belt now. BUT, I've got a question regarding the veg state.

Is there a definitive sign for when the seedling stage ends and the vegetative stage begins? I usually just consider 3 weeks from cracking the seed. I would like a more definitive sign though. Most posts say it's when "rapid growth starts". Thats not good enough I don't think. There must be some sign since "rapid growth" is very subjective.

I'd say when it's got 3-4 nodes and starts branching...No definitive idea though

the answer is as simple as the question. How big a plant do you want to end up with and why? If the reason is more yield, then look at this AK48 at 5 weeks from 12/12.

sorry , i think this is the right picture to demonstrate my point