For small ASNs wanting new connections it's getting pretty common for peers to require a RPKI/ROA (a cryptographic verification system used to automatically configure what advertisements are accepted based on what resources your RIR says you have and what you crypto sign on how you want to advertise them) instead of a LOA (letter of authorization, a document they can put on file saying what you intend to advertise). With this your RIR becomes the trust anchor (and signer, if you don't want to deal with delegation) so a revocation of the resources by the RIR should automatically result in your advertisements being rejected by your peering points in most cases like this going forward.

This is getting uptake because instead of the pitch to operators being "help validate internet advertisements" it's "now you don't have to manually configure accept policies or worry about misconfigured advertisements from clients".

https://www.arin.net/resources/manage/rpki/troubleshooting/#...