Driving Behaviour 

racing incidents 

If there is contact between drivers that doesn't put either out of the race but results in the guilty driver making up places on the innocent driver, we expect the guilty driver to allow the innocent party to pass freely to re-establish their respective positions as they were before the contact. Even if the guilty driver has to let other non-incident-related drivers past while waiting for the innocent driver to regain their lost respective position.

returning to the track after an off 

The onus is entirely on the driver returning to the track after an off to take all necessary care and responsibility not to interfere with any cars still on the track.  All on-track drivers have right-of-way over anyone returning to the track.

recovering from a spin or incident 

The onus lies on the driver, recovering from any incident that leaves them in any way an obstacle or a hazard to other drivers, to take all necessary care, hazard minimization, and responsibility not to interfere with any cars still on the track and not part of the incident. If you are off the track then the rules on returning to the track after an off apply. If you are on the track but in incident recovery mode, perhaps spun out, facing the wrong way, perpendicular to the track, going abnormally slow, you have no rights what-so-ever. You must give way to all non-incident-affected cars until you are fully recovered.

corner rights 

You must establish overlap with the car ahead before they reach the corner's turn-in point to have the right to drive up the inside and/or for room to be left for you by the ahead driver. Overlap means at least that the front of your car is up to the driver's position/B-pillar in the ahead car. You probably should have more overlap in many circumstances. The ahead driver has every right to be fully committed to the racing line of his choice without any interference if there was no overlap before he turned in. If sufficient overlap is established before the turn-in point, then the behind driver has the right to sufficient inside room. The ahead driver can still battle for the place of course but must leave room for the behind driver. The practice of going up the inside of an ahead car after they have already turned in, and where there was no established substantial overlap before the turn-in point, is sometimes referred to as barge passing, ( i.e. you barge your way past ). Understand that barge passing is a high risk manoeuvre for both you and others. You have no rights what-so-ever as a barge passer. The car on the outside has the right to the outer half of the track all the way around up to the exit point. They should not be squeezed against the outside towards the exit point. The car on the inside has the right to the inside half of the track all the way around up to the exit point. They should not be squeezed against the inside towards the apex area.

defensive driving 

The leading car has the right to choose their own line down a straight. They may make one move to block an attacking car to protect their position while on the straight. Then, naturally, as they approach the next corner, they can of course return to the racing line of their choice for the corner. The leading car has the right to take their line of choice through corners. They may drive a defensive line around the inside of a corner to protect their position, thereby forcing an attacking driver to try to pass around the outside. This is not blocking and is part of normal racing etiquette. In fact, apart from the restrictions of only moving once to block, a leading driver can choose any line that they feel is the most inconvenient for any following car to pass them.

driving a damaged car 

The driver of a damaged car is to take all necessary care and responsibility not to interfere with any other car. A damaged car has no rights what-so-ever over other cars. A damaged car in this sense means a car that for whatever reason is performing substantially below its normal performance expectations. The damage may be a mechanical breakage or failure of some kind on the car, or it may be an input control device failure, or whatever. The onus lies entirely on the driver to assess if they believe the risk of an accident to others is high enough that they should retire rather than continue.

lapped traffic 

There is no reason to contest being lapped. Drivers about to go a lap down, or are already one or more laps down should not block or race the cars attempting to lap them. It is up to the passing car to make a clean safe pass. The responsibility for a safe pass lies with the overtaking car.
At corner entry, don't slow more than usual going into the corner unless the other guy is already alongside you, or has already pulled out to show his intention/desire to pass at the coming corner. If you arrive at the corner and the guy is still behind you (especially if he's close), slowing right down and trying to go around the outside of the corner will likely end in you getting punted or, the guy passing spinning or destroying his front tyres trying to avoid hitting you, because he won't expect it.
At corner exit, don't try to let someone pass at the exit of a corner by not accelerating fully and/or moving over to the inside line before you've even finished going around the corner or soon after the corner. Stay on the racing line and exit the corner normally. The guy passing you will most likely be trying for a fast exit in order to pass you on the next straight. If you dive to the inside line you will baulk that move and potentially cause a crash. By not accelerating normally, you will also baulk the guy and cost both of you more time than necessary.
Don't try to let guys through in esses, chicanes or really short straights. Just drive through them normally and let them by at the next safe place. You don't have to let them through the instant they are behind you.
The best way to let someone pass is on a straight by staying on the racing line and just backing off on the throttle about 1/2 to 2/3rds of the way down the straight. That way the the guy passing can take the inside line into the next corner. Similar to a normal overtaking manoeuvre, just not contested and everything is nice and predictable. Being predictable and decisive is the most important thing. Make sure you check your display to see how many are there too and always keep an eye on it to check for faster cars coming through.
Whatever you do, don't slow excessively and don't drive off the track to let people through. The greater the speed differential, the greater the potential for disaster and driving off the track creates the potential for you to spin and makes everyone around you nervous increasing their chances of making a mistake too.
Most importantly though, everyone has an equal right to race. Everyone wants to be helpful and not get in each others way, but don't compromise your own race by throwing away several seconds every time you let someone by. If you just drive normally, stick to the racing line and let the guy slide by on the next straight or safe passing spot, then you will both lose less time and you won't blow your own chances of passing the guy in front if he makes a mistake.