A pacenote description covers far more than simple direction. It specifies the severity and character of every bend, the distance between consecutive features, adverse camber, crests that may produce airborne moments, jumps, surface type and condition, potholes, narrowings, and any special cautions the crew judges worth flagging. On a world-class rally stage, the notes for a single stage may run to many pages. The road book for a multi-day event such as a round of the World Rally Championship can fill several thick volumes.
The notes are written in a tight shorthand that varies by team, language, and tradition. There is no universal standard, but a handful of de facto systems are widely used. Severity of bends is typically expressed numerically, though the direction of the scale differs between systems. The British Club system numbers corners 1 through 5, with 1 being the gentlest kink and 5 approaching a right angle. The McRae system reverses this, with 6 meaning nearly straight and 1 a hairpin. Terms such as "square" (90 degrees), "oversquare" (tighter than 90 degrees), and "hairpin" (approximately 180 degrees) are common across systems. Distances are stated in metres or feet, with the unit assumed once a crew establishes their preference.
The use of detailed pre-written notes is associated with two notable victories by Mercedes-Benz in long-distance road racing of the early 1950s. Karl Kling and Hans Klenk won the 1952 Carrera Panamericana with prepared notes. Three years later, Stirling Moss won the 1955 Mille Miglia in a Mercedes-Benz 300 SLR with journalist Denis Jenkinson riding alongside as navigator, reading handwritten notes from a roll of paper — while other drivers competed without such support. Those victories demonstrated that meticulous preparation of route information could provide a decisive competitive edge in events covering thousands of kilometres.
From those roots, pacenotes evolved into the standardised practice of modern stage rallying, where reconnaissance runs before an event allow crews to compile their own bespoke notes across every kilometre of every stage.
The right to compile personal pacenotes depends on the rules of each event. Many events permit crews to drive the stages at reduced speed on official recce days before the rally, making notes from their own observation. The crew drives slowly enough to read the road, with the co-driver calling features aloud or the driver dictating while the co-driver writes. Notes are then transcribed, reviewed, and refined, sometimes using audio recordings from the recce run.
On some events, organisers provide an official set of pacenotes and ban private reconnaissance. In these cases the supplied notes become the only reference. Occasionally no notes at all are permitted, as in certain historic or adventure rally formats where the challenge is partially navigational.
When a stage is running, the co-driver reads the notes continuously, staying just far enough ahead of the car's position that the driver has time to react. The skill of pacing delivery — giving information neither too early to be forgotten nor too late to be useful — is one of the core competencies of a professional co-driver. The co-driver must also monitor the evolving road and be ready to re-synchronise if the crew loses their position in the notes, for instance after a spin or a near-miss that disrupts concentration.
Calibrated odometers with large digital displays are frequently used to help co-drivers maintain accurate positioning within the notes, counting down the distance to the next feature.
A sample extract of typical notes might describe a sequence as: "100 kink left 2, 100 kink right 2, 200 square left, 100 kink right 4, 50 caution jump into right 2 tightens, don't cut, 100 oversquare right, 400 flat to crest into kink left 4." In competition, the co-driver delivers this condensed form rather than spelling every word out.
Unusual features such as fords, cattle grids, or level crossings may be written out in full text rather than shorthand. Symbolic markings are also common — a pair of narrowing lines to indicate a road narrowing, or a bridge symbol for a hump bridge. These conventions are agreed between driver and co-driver before an event.
Sim racing titles featuring stage rally disciplines replicate the pacenote experience through audio co-driver calls. The call timing, terminology, and delivery style in rally simulators are modelled on real pacenote conventions, giving virtual drivers an introduction to the same anticipatory style of driving that pacenotes enable in the real sport. Understanding the numbering scale and terminology used in a given game's co-driver system directly parallels what a real rally crew must learn and agree before competing.