What does the OP_RETURN signify in this transaction?

[dwtguau]

I'm trying to understand what the OP_RETURN in this transaction (15c1d361fb7c5215050c16391c0445f1974f2c928a376b662ee1b4d85d46e416) signifies. It doesn't appear to make any sense when I try to decode it using UTF-8 or any online tool I could find. I've checked Ordiscan etc. and it doesn't seem to be linked to that. Anyone have any ideas?

[NotATether]

You can put whatever data you want inside an OP_RETURN output, even nonsensical gibberish. Or at least the data of a protocol that is not known to us - or one that was not published at all and was the product of some basement dweller's experiment.

There is no restriction that the OP_RETURN data has to be legible or in ASCII text.

[o_e_l_e_o]

That transaction is the Tx0 for a Whirlpool coinjoin. The whirlpool coinjoin server uses the OP_RETURN output to keep track of eligible coinjoin UTXOs, fees paid, and so on. There is no human readable component to these OP_RETURN outputs.

[DaveF]

That transaction is the Tx0 for a Whirlpool coinjoin. The whirlpool coinjoin server uses the OP_RETURN output to keep track of eligible coinjoin UTXOs, fees paid, and so on. There is no human readable component to these OP_RETURN outputs.

Minor quibble. But it IS human readable I can read it. It just has no human discernible data.

I deal with this from some database people all the time, I have to keep telling then that the DB admin can read EVERYTHING, so make sure any private data is encrypted BEFORE it hits the database.
Or, only be decoded in a way that the people with DB admin access do not have a way to get to.

-Dave