My 2002 Volkswagen’s manual specifically said not to use it to jumpstart other cars. The car was allowed to be jumpstarted, though. I don’t think it had any special instructions to do that, beyond the typical mentioned in the OP.
My BMW motorcycle had attachment points for jump starting it. The positive was (I think) on the transmission, near the foot peg, and the negative was on one of the cylinders. I always assumed that was because getting to the battery required removing the fuel tank, so it would have been impossible to jump start without the remote terminals.