Help with an older version of a dead game

I like to mess around in a older build of that infamous Monster game, as it’s a lot of fun, but I have an issue.

I’ve figured out the majority of the movelist, but at the bottom of each there is one that shows the desired input, and ends in +S. I have no idea what key input the S stands for, I can only assume it is a multi-press command.

Anyone know what it is?

This really is a great question to ask in this thread: FGD Lounge: for general fighting game discussions that aren't thread worthy rather than make a completely new thread.

Alternatively, you could consider necro’ing the Monster thread, which is definitely on FGD heere somewhere.