There utxo for currency terms, if you want to spend coinbase transaction, whether the transaction was first detected coinbase thaw. Blocks will have to detect the latest generation coinbase height minus the height of the block is greater than the set value COINBASE_MATURITY, if the difference is greater than or equal COINBASE_MATURITY, proved at least confirmed after COINBASE_MATURITY blocks, that amount has been thawed, the freezing medium is conversely .
The coin denomination bit lines btc, ltc, bch, bsv "COINBASE_MATURITY" value 100, qtum "COINBASE_MATURITY" value 500