Negative signs. Ptolemy sights two categorizationsin Tetrabiblos, serving here as historian. 1) The even numbered signs: Taurus, Cancer, Virgo, Scorpio, Capricorn, and Pisces (the other signs being masculine). 2) The sign rising is deemed masculine and the signs thereafter are categorized in one of two ways: a) the signs simply alternate in zodiacal order, house by house; or b) the signs on the cusps of houses 4, 5, 6, 10, 11, and 12 are masculine (opposite quadrants, SE and NW), and the signs one the cusps of the other houses are feminine (the remaining quadrants). It is thought that Ptolemy used Equal Houses or a similar system, so presumably interception of signs would not have been an issue.