Who coined this term? Does it mean "cross-boot," or does it have something to do with XBAND? Is it official Nintendo terminology or scene slang?

As far as I know, "Xboo" was a "brand" of sorts for no$gba developer Martin "nocash" Korth's boot loader cable designs. At the time, Xboo for GBA competed with the mass-produced MBV2 cable for GBA multiboot.

Ah, ok then. I did just find my GBA and need a way to connect it to test. Nocash describes four methods for connecting an Xboo cable to a GBA, but unfortunately all of them are invasive or destructive in some way:

https://problemkaputt.de/gbatek.htm#auxxboopctogbamultibootcable

I definitely feel more comfortable destroying a third-party link cable than a Nintendo one, so I'll probably go that route.

Any idea what AUTOLF means? Automatic linefeed?