There is something strange(r than usual) going on at the PHL checkpoints. B and C have not had priority lanes for a while now, and the C checkpoint has been closed completely based on "flow" at times during the day. A-East has a priority lane, but you need to ask about it, the signage is horrible. Pre-check hours are all over the place. If you comment on Twitter to @PHLAirport, they will quickly respond that either the airlines setup priority arrangements (and will copy them in the reply) or that TSA controls checkpoint duty (also copying them).