zpubs or Zpubs are bad ideas. They should not have been created. And there are plenty of misunderstandings out there.
Since zpubs or Zpubs are already for P2WPKH or P2WSH, then what's the alphabets for taproot?
People should always use xpub and descriptor.
xpub is for the legacy 1 addresses.
Taproot doesn't have its own extended version bytes because Taproot UTXOs also are P2WPKH just like native segwit, so they use the same "zpub"/"zprv".
On the other hand, if you are using Taproot leaf spending feature, that's also an extension of P2WSH bc1q script addresses and so you should also be using "Zpub"/"Zprv" extended version bytes.