This structure has been used by many cultures and through many
ages. During the Middle Ages was used in Europe to
denote the moon.
In modern musical notation is called fermata and signifies that a tone should be hold longer than its normal time. In astrology represents the quadruplicity or quality mutable of a zodiacal sign. The mutable signs of the zodiac are , Pisces; , Gemini; , Virgo; and , Sagittarius. here stands for signs indicating ending phases of orbital movements, as , the fixed quality, stands for signs indicating phases with no change, and , the cardinal quality, stands for signs indicating beginning phases. The background for, and meanings of the quadruplicities or qualities, are explained in "The astrological sign system" in the Appendices.
Persons with many planets in mutable signs are considered to be intelligent, flexible and able to adapt quickly to changing circumstances.
In the U.S. system of hobo signs means look out the authorities here are on the watch. The sign inverted, , means in this community they don' t trouble hobos.
In some meteorological sign systems is used to represent rain that does not reach the ground. The uniting quality of , in accordance with the law of the polarity of meanings of elementary graphs, here adopts an opposite, isolating signification.
Compare with , precipitation far from the observation station.
See also in Group 20 and in Group 8.