“Black tag” means it is tagged non-operational.
“Bought this awhile back to fix up obviously it’s not happening $5,000. 1948 Willys Jeep has a 302 in it the transfer and transmission is stock. It has a new aluminum radiator I don’t know too much about it I bought it I gave it a lift and when I did the lift it slowed me down on everything I can tell you what I know I have title in hand tags are current but it is black tagged”
https://tulsa.craigslist.org/cto/d/1948-willys-jeep/6302111190.html