Does the 24h/48h/72h JUMP pass for Brussels need a MOBIB card, or can it be obtained as a standalone ticket? The STIB website gives different answers in different languages:
Yes it does. The English description is not up to date.
There is also a "JUMP 1 day ticket", which is valid until the end of the day it has been obliterated. This one is still available as a "traditional" magnetic card.
Source: STIB Transport rules https://www.stib-mivb.be/vervoer_transport.html?l=fr
If you want a 24/48/72 hours ticket you can also ask for a so-called MOBIB Basic card. It is easier to obtain as it is not personal.