NoteCarrier-F Rpacks on M.2 connector purpose?

Can someone tell me the purpose of the 2 100 ohm rpacks that are on the M.2 connector on the NoteCarrier-F schematic? (also on NoteCarrier-AF schematics)

I am trying to figure out if they are for I/O protection due to different voltages that could exist between the NoteCard and Carrier board OR if they are for slewing signals that are too fast???