Can someone tell me what this MicroATX variant is called?
It measures 9.5 x 6.75, almost the exact height of Micro-ATX and width of Mini-ITX.
This board is fron like 2009. I got it like 10 years ago, and remember reading this form factor was somewhat standard, being used by other companies, and having a name. But I cant remember.

The manual for the board calls it "Flex/Micro ATX". But Flex ATX is 9" x 7.5" and can only fit up to 3 expansion slots.