0xd547741f?0xd547741f is the function selector for revokeRole(bytes32,address). Removes a privileged role.
When a transaction's data begins with 0xd547741f, it is calling revokeRole. The selector is the first four bytes of the keccak-256 hash of the signature revokeRole(bytes32,address), which is how wallets and explorers work out which function a payload is for.