Pete Lacey - The S stands for Simple:

"SOAP Guy: On the bright side, nobody uses the Doc/Lit style anymore. In order to get transport independence back we’re all using wrapped-doc/lit now. Doesn’t that sound cool: wrapped-doc/lit?

Developer: What’s that?

SG: Well, it’s just like Doc/Lit, but you take the whole message and wrap it in an element that has the same name as the operation. Now the operation name is back in the message where it belongs.

Dev: Okay, where’s the spec on this?

SG: Oh, there is no spec. This is just what Microsoft seems to be doing. Looked like a good idea, so now all the cool kids are doing it."