Sheldon; you're kidding, right?
It just so happens that I own all four Superman movies, and I've been having my own Superman Marathon.
For years I've assumed that the "S" logo on the front of Superman's nifty little flying suit stands for "Superman".
Probably the rest of the world thinks so too.
Or maybe it's just me.
Aaaanyway.....near the beginning of the first movie, we see Marlon Brando as Superman's father, Jor-el, in that whiter than blindingly white suit, with a very similar "S" logo on the front, while the rest of the Kryptonians*, also wearing blindingly white suits, have different logos.
Senator? Shopkeeper? Shoemaker? Scientist?
Smith? Scott? Stanfield? Sheldon?
A Kryptonian version of "$"? thereby proclaiming Jor-el the richest man on Krypton, certainly the only one rich enough to create a crystal star bubble capable of transporting Kal-el through space all the way to Earth.
(Wonder why he didn't save himself and his wife too?)
If anyone out there has any other ideas as to what the "S" means, I'm happy to listen.
No matter how fanciful those ideas may be...
*aka Planet Napisan.