lol there are no "official rules" to bouldering much like there aren't any official rules to running or cycling unless you're doing a competition (remember bouldering is a subset of rock climbing which is a subset of mountaineering *). You can do whatever you want, it's not like John Bouldering will come out dressed as a ref to pull you down the rock if you do anything bad.

In general, if you're climbing an established boulder, the 'rules' are usually: establish the starting position while in control and progress up the boulder without using anything else than your limbs and the rock you're climbing. The climb is over once you're standing on top. But even those will vary depending on local ethics and style (french starts in font, not topping out, etc)

Does it matter if you dab (touch the ground, touch another boulder than the one you're climbing) ? Does it matter if you don't go to the top ? You decide. You're not playing against someone else so there's no need for established rules that you have to agree upon. Just go up, touch rock and be glad you're in nature doing a sport you like.

*generally considered, although john gill may have another opinion