That would be covered in this part of the
GTP OLR:
"Leading cars have the right to choose their own line down a straight. They can change their racing line
once while driving down a straight (Move from the outside line to the inside, or vice versa). As they approach the next corner, they can return to the racing line of their choice However, they're not allowed to change their line when the behind driver is directly behind and changes his line to try and make a pass. If your movement causes an accident, you're responsible."
I think we should all take the time to read through the entire OLR before today's race. There seems to be some differing thoughts on what constitutes right of way when it comes to passing. Section "08: Corner Rights" gives a good explanation of this, better than FIA or SCCA rules in fact 👍
Since today's race also includes pit stops, the OLR also has a whole section on that too.
It's Turbo's series, so I'll let him make the ultimate decision on the rules, but it's my understanding that we are following the GTP OLR for race conduct.