Refreshed BIP324

The Bitcoin Improvement Proposals (BIPs) repository has undergone changes following a discussion about the use of short 1-byte message type IDs. The changes are now available on a pull request made on GitHub. The discussion centered around the complexity of the negotiation process for mapping tables and the need for re-negotiation of short commands after they have already been in use. It was suggested that if all negotiation of the mapping table occurs before VERACK, and without use of short commands, there would be no need for re-negotiating short commands. This would simplify some implementations and allow each BIP324 node to use a single short ID mapping for all outgoing messages. The proposal was well-received and further discussion is expected.