So, OP_RETURN is here and there is no coming back. So if we have it, it would be nice to actually make use of it in a good way. I would like to write a process BIP with a proposal for standardizing OP_RETURN transactions for better interoperability between services. Right now there are no guidelines for crafting these transactions, so everyone just does what he believes is good for him. What I would propose is a common, extensible protocol that can be used by anyone. The generic format would be like this: OP_RETURN OP_PUSHDATA[length] {2-byte message type} {data} So basically, we would have a list of message types, that can be then parsed by everyone because the format is open. It could go like this: MSG Type | Parameters | Description 00 00 | unknown | Unused type, use it if you don't want to share your message format with others 00 01 | none | Proof of burn transaction. Use it if you want to effectively destroy coins (by sending it all as fees to miners) ... And so on. I have few more ideas for these kind of messages, but it will only work if we try to make it an open standard, hence the BIP idea. Can I expect that it will be included with other BIPs if I write it? -- Best regards, Maciej Trębacz - Bitalo.com