The identity code must be generated from https://keybase.io which looks little bit unserious, because it’s not decentralised. What will happen if this website stop working tomorrow?
If this service is the only way to create a full validator node, then I have a proposal - implement some other decentralised system to replace keybase.io… with avatar censorship votings etc. because doing it that way is little bit unserious and unstable.
From my understanding, the field is optional, and can contain any sort of cryptographic identifier. The only advantage of using keybase there is it ties your validator to your avatar. If for some reason keybase went away, I’m sure the community would figure out another way to do that.
Keybase is very serious and they do publish events to the Bitcoin blockchain. So if Keybase was to disappear and Bitcoin is still around, it should be possible to still verify someones proofs and identities: