Too bad pauper isn't new... also when you use paper backed cards its called paper pauper.
Pauper is a format for MTGO where any card released on MTGO as a common can be used... Paper pauper is a format that doesn't have official rules or banlist but in general allows for any card printed as common in any set allowed, restrictions will be set in place by play group or hosting party(i.e. if a LGS hosts a game of pp)
Yes, you are right. It's not that new as my post might let you guess. And I am sorry for this. But I don't play MTGO so it was new for me even though I already play Mtg for a while. More or less there is a banlist and a ruling text: https://magic.wizards.com/en/game-info/gameplay/formats/pauper