...and, because I have a few mental problems, it is nearly IMPOSSIBLE for me to remember this naming scheme, so I'll post it for 'tards like me to refer to:

Internal SD =
mmc2
mmcblk0

External SD =
mmc1
mmcblk1

Now how does that make any sense? More convoluted linux maddddddnesssssss

(I feel a bit like Alice, slipping down the rabbit hole)