On Jun 15, 2015 11:43 PM, "Rusty Russell" <rusty@rustcorp.com.au> wrote:

> Though Peter Todd's more general best-effort language might make more
> sense.  It's not like you can hide an OP_RETURN transaction to make it
> look like something else, so that transaction not going to be
> distinguished by non-canonical ordering.

What about commitments that don't use op_return (ie pay2contract commitments)?

In any case, if the motivation is ordering in multi-party transactions there should be ways to do it without any consequences for other transaction types' privacy. For example you could have a deterministic method that depends on a random seed all parties in the transaction previously share. That way the ordering is deterministic for all parties involved in the transaction (which can use whatever channel they're using to send the parts to also send this random seed) while at the same time the order looks random (or at least not cannonical in a recognisable way) to everyone else.