Except that everyone, from the security people to the gate agents, looked at my self-printed BP as if it was the first time they'd ever seen anything like it. And the charming young ladies at the lounge refused point blank to let me in simply on the basis of my PYOBP piece of paper - I had to wave a Gold card (now sadly out of date) at them to get in.

BTW, if anyone needs a little longer in London before flying out to Moscow, there's a great Swiss connection through ZRH which is incredibly civilised and gets into DME around midnight. The ZRH-DME plane is normally nearly empty in C - a big difference from the claustrophobic atmosphere on the BA planes.