You guys are incredibly responsive. I might try to sign a transaction with the key that allowed me to donate 5 BTC to Bitcointalk. But that goes way back. It doesn't seem simple to me!
During that time, I talked a lot about Ripple, and XRP wasn't well-received on Bitcointalk. I irritated some people and ended up "trolling," which resulted in a ban. This must have been around 2013 or 2014.
I tried several times (in 2014, 2018, and 2022, i have many mp's with différents moderators, i can post it) to recover this account by questioning the moderators of the French section. It was only tonight that n email "locked_2019_vuhnu" asked me to create this kind of thread in this section. What I am finally doing... I know, it's late!
If you can sign a message with another coin that would also help. If you've got addresses in your PMs they could also be used if we can verify them.
Maybe it was just a temp ban. You're unlikely to get permabanned for trolling unless you've had multiple warnings and bans and still won't stop.
Edit. It seems there is actually two bans on the account. The other is for "Alt currencies content outside of Alt currencies board" which doesn't have an expiration date. Maybe one was forgotten to be put in because that also is unlikely to get you a permaban unless you're a serial repeat offender. Either way, op is going to have to sign a message if he wants the account unlocking.
There is no single wallet associated with this account found, and no BTC address on his profile, so what and how will he sign a message to authenticate account ownership?
He probably can't so he's probably SOL but it's best messaging the recovery team to try work it out.