[LegionMammal978]

They aren't actually floating-point: each label is a pair of numbers, the first denoting the group and the second denoting the line within that group. The groups have no semantic importance, they are only for organization.

[LegionMammal978]

Actually, I was mistaken. The line numbers aren't even numbers, so much as digit pairs, given how one-digit labels take the first digit.

And the "DO" command takes a group number, runs each line within the group, then returns after the end of the group. So each group can effectively act as a subroutine. (In this particular game, this can be seen in groups 6 and 9.)