[Cn-H]1..8
[sigma(n,n+1)]1..3,5..7;
sigma(4,1);sigma(8,5);
[sigma(n,n+4)]1..4
and
C1-5,H-C2-6,H-C3-7,H-C4-8,H,1;
C5-H-C6-H-C7-C8-H;
and
[Cn-n+4,H]1..4;
[Cn-H]5..8;
sigma(4,1); sigma(8,5);
They all represent the same carbon cube. (C8H8)
Purpose; because the normal naming of chemistry can’t define all structures they come up with trivial names, which I find very annoying. This notation is intended to be able to describe every structure uniformly. And no, don’t even try to pronounce it.