An ‘Indult’ is permission by the Authority to do something that is normally either prohibited or outside the Normal way of doing things.
While most commonly refered to in Catholic conversations to refer to permission by the Bishop to say the Tridentine Latin Mass, other indults exist
For example, it is Normal procedure ( Norm) for deacons or priests alone to ‘purify’ or clean the vessells used at Mass.
But the US has an ‘Indult’ for lay people to do so if necessary.
Special permission to do what is otherwise prohibited…
“Novus Ordo” or “New Order” is a common, though incorrect, term for the Pauline Mass Mass, the Missal created after Vatican II under the auspices of Pope Paul VI.
The latest version of that Missal is the 2000 Missal (3rd Edition), but the translation of that from Latin is still in progress, so the US is still using the 1975 Missal (Missa Romanum 2nd Edition -1975)