Bitcoins early implementation had a way to prove you own a specific key, called bip 57. With newer addresses such as segwit and taproot this method doesnt work anymore. This is why bip322 was introduced
Bip322 creates a standardised way to sign a pbst message. The bip was finalised in march 2026 but nog implemented in seedsigner yet. Coldcard does support the bip322 messages
Bip322 message signing was implemented by the Bitcoin Parasite Pool to prove ownership of addresses that are mined to, especially to set the lightning payout address when a block is mined and rewards are distributed