for those still interested: 8, 2, 4, 6 are obviously numbers on the keypad on the keyboard. Like, literally, if you look at the right-hand-side of the full-sized keyboard, these four numbers have arrows printed on them: 8 is up, 2 is down, 4 is left and 6 is right.

dont think is an issue

But the tail is a 1 char string

It's done for many old games because this allows you to:

dx = (dir%3)-1
dy = (dir/3)-1
dir = (dx+1)+(dy+1)*3

In any case, it's arbitrarily defined anyway and it's perfectly fine to define them as sqrt(2), pi, e, Infinity too (even though that'd be bad and ridiculous).