On: Corporation Says It Will Run for Congress

[Semiapies]

In practice, you see both: http://en.wikipedia.org/wiki/USSC

[ynniv → Semiapies]

A Wikipedia alias counts as evidence of usage? I've never heard USSC either. Google thinks its United States Stove Company, or United States Sentencing Commission: http://www.google.com/search?q=ussc

[Semiapies → ynniv]

Well, yes, as it's a use, it's evidence of use. I didn't exactly invent it. :)

Try googling +ussc "supreme court". It's a less-used, but real initialism.

[ynniv → Semiapies]

Points for "initialism". I was about to write you off as a neologist, but then I learned that most acronyms are actually initialisms.

[elblanco → Semiapies]

I use USASC, but that's even less used.