A group of three solid lines alternates with a group of two ledger lines. The staff has a 7-5 line pattern much like the Mirck version of Klavar. The notes in the spaces between the lines are the notes of the C major scale (the white piano keys), and the notes falling on the lines are the the other five notes of the chromatic scale (the black piano keys). Between the groups of two and three lines there are two adjacent spaces without a line separating them that represent the notes E, F, and B, C. The physical distance between the two groups of lines is equal to 1.5 spaces so that the vertical spacing of the notes is even and pitch-proportional.
Earliest documentation: 1989
Source: Directory of Music Notation Proposals, section/page: 13/63