Anti-transaction replay in a hardfork

Lau proposed an opt-in system, while Harding's proposal was opt-out. Upon realizing the difference, Harding expressed concern that Lau's proposal would require modifications to already compatible systems, making it unlikely to be included in new network designs. However, Lau clarified that their proposals were essentially the same, with the only difference being the use of a bitwise not before the network characteristic byte. This clarification led Harding to agree that an opt-out system would make more sense for everyone involved.