Official mobo form factors

[SUOrangeman]

I'm starting to confuse myself when matching cases and mobos. What are the official mobo form factors?

ATX
Micro ATX (mATX)
WTX
other (huge server boards?)

The confusion sets in when looking at cases, as such options are available:

Tower (ATX)
Desktop (ATX)
Mid-Tower (usu. ATX-compatible/compliant)
Mini-Tower (maybe ATX, likely mATX?)
Other?

-SUO

 

[AndyHui]

Custom
WTX
ATX
microATX
FlexATX
NLX

http://www.formfactors.org