What does SECC steel mean?

Greetings,

I was hoping someone would be kind enough to explain to me what SECC steel means with regard to the material use to make PC cases/chassis.

i.e I see them mentioned as being made from 1.0mm SECC Japan Steel. What does the SECC stand for and what does it actually mean with reagrd to the steel?

I would guess it refers to some type of coating with reagrd to rust prevention but, it would only be a guess.

Thanks.

Toyo