Where the baseball cap begins.

The small of their backs, where there is usually a tuft of crack hair

Where does the butt start?

Foreheads wrinkle when you frown, hairless scalps do not. Edit: headless -> hairless

Where it ends for most people, at the edge of their scalp. The area where the hair used to be when it was still growing

You just keep adding 1, so it becomes a fivehead, then a sixhead all the way up to slaphead.

It never ends, unlike the hair.

Coccyx.

A fourhead is only as far as four finger widths from your eyebrows. I myself have a fivehead.

It just goes all the way round. Bald men are literally dickheads.

At the start of the five-head.

If standing straight, roughly at 110° from the floor.

At the mullet

Directly above the asscrack.

Directly above the asscrack.