I thought the admin might delete it for me. But yeah, I should explain for anyone looking with the same question.
A listing for a seal for my 2010 Ranger's transmission at Rock Auto said it was for a M5HD, but I had heard my truck has the M5R1, so it got me wondering which transmission is in my truck. Then I found that on the door sticker the transmission code is "R". That had me stumped so I posed the question on here.
I ended up finding the answer in my 2010 owner's manual (DOH!) and code R is for the M5R1, and code J is for the M5HD.
I think Rock Auto was maybe listing the transmission for my truck wrong on the part I searched because the same part might fit both transmissions. At the same time it was confusing to see the wrong transmission listed for my truck because I had put in my correct year, model, and engine size.