Families 1 through 8 depict basic figures, such as turns, loops and vertical lines; family 9 depicts rotational elements that can be added to basic figures to increase difficulty, change the direction of flight or invert the g-loading of the aircraft.
The catalog assigns each manoeuver a unique identifier, called a catalog number, and difficulty factor, represented by the symbol K. When a basic figure is combined with one or more rolling elements, the resultant figure K is the sum of all component Ks.
During an aerobatics competition, judges grade the execution of each manoeuver with a value between 10 (perfect) and 0 (highly flawed).
[2] José Aresti's development of a notation for aerobatic figures began while serving as an instructor in the Jerez Pilot Training School in the 1940s.
[2][3] Following Aresti's death, a court fight ensued between his heirs and FAI, which once provided a free catalog online.