Marine Toilet & Black Tank
 

I'm looking at a build sheet for a 2012 E-350. It shows a marine toilet. Does a marine toilet have a black tank?

It just means the system is self-contained, that is, it can operate without connection to a shore-side (city) sewer system. So yes it has to have some kind of holding tank. Note: porta-potties are technically marine toilets.

Depends on the individual chronicling the description.
Normally I would assume YES.
There are hand-Pump Marine toilets & Electric Marine toilets which would both require a black tank. BUT, then you have situations where someone lists a "portable" toilet as a Marine Toilet. Probably because the manufactures sometimes refer to theirs as a 'marine toilet' in the description of these. So would confirm with the seller just to be sure.