Where do the GSL league names 'Code S' and 'Code A' come from?

Question

The Global Starcraft League has subleagues called 'Code S' and 'Code A'. Where did these names come from, and do the names have any special meaning?

Answer 1

Because having a B-rank of players sounds bad. A-rank (Code A) players are still excellent, hardly deserving of a paltry, average, "B" grade, so they just shift up the top to something else: S.

As far as what they are, Code S is the big time league, while Code A has been likened to the minor leagues (though still quite an achievement)

More on this S thing from Giant Bomb's "S-Rank" article:

‘S-Rank’ is a term used in games, most commonly awarded at the end of stages with graded missions or side objectives.

Originally created in Japan where anything below grade ‘C’ was considered a failure. The 'S-Rank' [...] If the player is flawless or achieves perfection in something, it qualifies as an S. Many people have wondered what the S stands for… Special? Super? No one knows for sure.