Block Version History
| Version Number | Proposed In | Released | Summary |
|---|---|---|---|
| 0x20000000 - 0x3FFFFFFF (bits 13-28 vary) |
BIP-0320 | Not released (draft BIP, assigned Mar 2018) |
Bits 13-28 (integer mask 0x1FFFE000) reserved for general use, such as extra nonce space for miners. |
| Aug 2017 | Bitcoin Cash hard fork. | ||
| 0x20000000 - 0x3FFFFFFF | BIP-0009 | Apr 2016 Bitcoin Core 0.12.1 |
Version bits: the top 3 bits are 001 and the remaining bits may signal soft-fork deployments. |
| 4 | BIP-0065 | Nov 2015 Bitcoin Core 0.11.2 Enforced from block 388381 (Dec 2015) |
Added support for OP_CHECKLOCKTIMEVERIFY opcode. |
| 3 | BIP-0066 | Feb 2015 Bitcoin Core 0.10.0 Enforced from block 363725 (Jul 2015) |
Added enforcement of DER encoding of all ECDSA signatures in new blocks. |
| 2 | BIP-0034 | Sep 2012 Bitcoin Core 0.7.0 Enforced from block 227931 (Mar 2013) |
Added the block height within the block coinbase. |
| 1 | Jan 2009 | The format used in the genesis block. |