How about generalize it to any popular base?

[MaxGraey]

See:
https://github.com/cryptocoinjs/base-x

Often in some domain areas users required Base58 (Bitcoin, Ripple and others crypto addresses)
Base85 also have standard (RFC 1924)

[bakkot]

Thanks for the suggestion. I'm closing this a duplicate of #7; feel free to continue the discussion there, though for either of these to be included you'd need to make a case beyond "there is at least one area which uses it".