ranks turns with 1 being the gentlest of bends, and with 5 being almost 90 degrees. The "McRae in Gear" system ranks turns with 6 being almost a straight line, and 1 being a hairpin turn. A similar numbering may also be used to denote the gear in which the corner is to be taken. The term "square" is used to indicate a genuinely 90 degree bend, and "oversquare" or "square plus" for even sharper. "Hairpin" is used for 180 degree bends or almost as much. Crews will agree a system such that the speed at which a bend can be safely negotiated is understood. A top rally driver will implicitly trust their co-driver, and be fully committed according to the information they are told. Good notes and good teamwork are essential for this approach to work. Unusual features such as a ford or grid might be written out in full, rather than in shorthand. Other symbols that are not strictly text are also used, such as a pair of narrowing lines to indicate that the route narrows. Crests and bridges are also often indicated symbolically. When pacenotes are read, the co-driver will not translate into the fully worded text given above, but instead will keep some abbreviations, such as 'K' for a bend or kink. Distances are just given, the units are understood. The above notes might be read as: 100 K left 2, 100 K right 2, 200 square left, 100 K right 4, 50 caution jump into right 2 tightens, don't cut, 100 oversquare right, 400 flat to crest into K left 4, 100 finish. The co-driver will read the notes at such a pace that the driver will always have enough to go on, but not so far ahead that they will have forgotten it by the time the feature is encountered. This pacing is something that comes with practice and development of teamwork. Often the co-driver will need to "get inside the driver's head", and re-read notes that they think might have been forgotten, or for emphasis. Sometimes the driver might even ask for some notes again. The co-driver must also match up the notes to the actuality of the route being driven. Re-synching the notes with the actual route after a loss can be tricky, depending on the terrain. A good co-driver will always seek to prevent this happening. Aids to accurate use of