There seems to be a reasonably standardized format for some, but not all, commit messages in bitcoin's git repository. For example, in addition to the usual expository commit message, this commit (https://github.com/bitcoin/bitcoin/commit/270616228bc9a3856a0a82dea26ac3480b7585cd) also includes:
ACKs for top commit: MarcoFalke: ACK 0e7c90e crocodile fanquake: ACK 0e7c90e Tree-SHA512: 6d954a0aaf402c9594201626b59d29263479059e68fa5155bb44ed973cd0c3347729dd78b78b4d5a2275e45da365dc1afb4cc7e3293dea33fcc2e3e83a39faf5
There are many commit messages with similar structure. As these commits get buried under other commits, this is quite reminiscent of aspects of the consensus mechanism that the bitcoin protocol itself uses.
In other words, if we squint hard enough, it seems like the commit messages themselves partially encode a slow-enough-for-humans-to-interpret blockchain.
For reference, here are some issues (https://github.com/bitcoin/bitcoin/issues/16200 and https://github.com/bitcoin/bitcoin/pull/16223) where some discussion about the content of these messages is taking place, but unless one is already a core contributor, it is difficult to pick up what is going on from context here.
Is there any documentation, informal or otherwise, about how/if these messages might encode aspects of consensus among the contributors?