What for, then? 🤔 I always thought that OP_RETURN was for arbitrary bytes.
Discussion
Apparently it was to burn bitcoins but you’ll have to be crazy to do that. https://en.bitcoin.it/wiki/OP_RETURN
They exist, though! https://twitter.com/YoshishiSatoshi/status/1668345218821939200
OMG Thank you for your donation guys 🫡😂
Smart contracts. It indicates the transaction spending is invalid.