Rain tyres
Better known as wet weather tyres. Tyres made from softer compound and with heavy grooving to allow water exit between tyre and ground. Rain tyres wear out faster due soft compound and smaller footprint.

Reconnaissance, Recce
A period of time before the rally when competitors are allowed to drive through the stages in order to make their pace notes. Speed is limited to what local legislation says, which makes it hard to judge how corners look like at rally speeds. Number of allowed passes has decreased steadily, from days of free practice to three or even two.

Regroup
A stop between certain stages scheduled to bring together cars still in rally. No servicing is allowed.

Ride height
Distance between road surface and bottom of the car. On tarmac cars are generally set up very low, much lower than on gravel. Gravel specifications vary from event to event, on smoother gravel events ride height tends to be lower than on rough conditions. From performance point of view, lower rideheight is desirable as it makes car less nervous as body does not roll as much.

Road book
A set of instructions and route maps issued to each crew by rally organisers. Originally developed by Tulip Rally organiser Piet Nortier from the Netherlands (hence the name), it has now been adopted by all WRC events. Book uses symbolic depictions of junctions with distance between each one, doing away with the need to navigate with maps and reliance to road numbers, village names and landmarks.

Road section
Section between two time controls that is not stage, regrouping or service area. Road sections are not closed to other traffic and hence, normal traffic laws apply which rally crews must respect like any other motorist.

Roll cage
Roll cage is primary safety feature on modern rally cars. Consisting of high-strength steel tubes welded into form of a cage (hence the name), roll cage is perhaps the only part of a rally car where weight savings are not even considered. In case of an accident, roll cage protects the crew and fuel tank from worst damage.

Roo bar
Australian version of bull bar. Exactly the same thing for the same purpose but name comes from kangaroos instead of bulls.

Running order, road order, starting order
The order in which competitors enter the stages, usually fixed for the whole leg (day), but can change due to regroups (for example publicity stages like Super Specials or Power Stages are usually run in reverse order) or individual competitors being late. Running order for the first day was championship order until qualification was introduced in 2012. Running order for the subsequent days was rally classification but is currently reversed for top drivers (though rule has changed several times).

Ruts
Ruts form on stage surface when consecutive cars repeatedly run over the same spot, usually on corners. Heavy rutting becomes serious problem on softer surfaces and is very common when stages are run more than once. Ruts are especially difficult for later runners and two-wheel drive cars.