Off the highest of my head …
ExtraNonce: In addition to the Nonce discipline, There may be additionally an extranonce conference – part of the unlocking script within the enter of the coinbase transaction is used as an additional nonce by miners.
Timestamp: The miner can range the timestamp. It solely needs to be correct inside about 2 hours. It would not need to be larger than the timestamp of the earlier block.
Coinbase output: The miner can range the coinbase output. Maybe deciding on a distinct receiving tackle or various the kind of script.
Transaction order: The miner can range the order of transactions (aside from for transactions that spend outputs of prior transactions in identical block).
Transactions: The miner could make an arbitrary choose of transactions from their mempool or create their very own new arbitrary legitimate transactions to incorporate. If inventing their very own transactions they’ll range the payment from zero to most and may range the transaction kind from legacy to newest. They will additionally range the enter quantities from close to zero to complete UTXO. The transactions should be legitimate however that also permits an unlimited vary of variations, assuming the miner owns some bitcoin to begin with.
Desk 2. The construction of a coinbase transaction enter
Measurement Discipline Description 32 bytes Transaction Hash All bits are zero: Not a transaction hash reference 4 bytes Output Index All bits are ones: 0xFFFFFFFF 1–9 bytes (VarInt) Coinbase Information Measurement Size of the coinbase information, from 2 to 100 bytes Variable Coinbase Information Arbitrary information used for further nonce and mining tags. In v2 blocks; should start with block peak 4 bytes Sequence Quantity Set to 0xFFFFFFFF
See additionally BIP-34