The 'cut' off top leading edge of the card is called the 'retrograde'
when talking of a IIgs card. It means it can fit in a IIgs or //e
case. Though obviously the frontward reaching part of all A2
peripherals had to be angled as all the cases were like this until the
IIgs. At the time of the IIgs, if you didn't care for your hardware to
work in system that was an upgrade, you could skip the retrograde.

The RAMKeeper is such an example. As well, the MPD/PBC 4 Meg Expander
RAM card. These don't fit in a //e case with the lid on.
--- SBBSecho 2.12-Win32