Why does roflcopter have an empty protocol line in the consensus?
r roflcopter Qcrc8IhWf84BI34AQRKJU5q7EpU 2017-09-24 03:25:06 188.8.131.52 443 80 m EDFeSxWDaRrY9S2ZROrxpABlrFPqnJQ7IbYXpEdkQao s Fast Guard HSDir Running Stable V2Dir Valid v Tor 0.2.9.11 pr w Bandwidth=7110
The descriptor looks reasonably normal. There is no Sybil on that IP address. https://atlas.torproject.org/#details/41CADCF088567FCE01237E00411289539ABB1295
It is blank in all the votes too. It's blank in the vanilla-flavored consensus too.
What would cause the "pr" line to be left blank?