I'd consider it enumeration. A=1, B=2 is no different than 1=A, 2=B, which is what you're doing. Every character is enumerated, assigned a number, and then you arrive at a meaning by iterating through multiples of a given number.
No, that is not it.
They don't assign anything. It's simply reading, but skipping over some of the characters. The only place where the number comes in at all is in identifying what the particular spacing is. The spacing is something that has to be found by examination of the text; you can't just decide for yourself; it's just what is there.