Quarter-, third- and sixth-tone accidentals

The system of microtonal accidentals I've been using for most of my music. (Though a quarter tone would be at least vaguely 50 cents, a third tone 33 cents and a sixth tone 17 cents, this is not for exact 72-edo--I use a similar but different system for that.)

The sixth-tone sharps and flats (the natural signs with arrows) are also used when a third-tone accidental is combined with a regular one, e.g. third-tone sharp plus (half-tone) flat equals sixth-tone flat.

These symbols are contained in fonts available in Finale and Notepad, and also Sibelius and the Scorch reader.