Dusturiyyah
Definition
Dusturiyyah (Arabic دستورية, from the Greek doryphoria, 'spear-bearing, bodyguarding'; Latin dexteratio) is the Arabic-Persian condition in which planets act as 'bodyguards' of the luminary of the sect and so raise a native's social rank. Diurnal planets oriental of the Sun by day, or nocturnal planets occidental of the Moon by night — especially when in their own domiciles or exaltations, on angles, and aspecting one another — attend the sect-light like a king's guard. It is the chief Arabic-tradition test of eminence and royal status.
In Tradition
Arabic-Persian astrologers read dusturiyyah as a graded signal of how high a native rises. 'Umar al-Tabari, drawing on Ptolemy, ranks it: when the superior planets and the Sun are all in their own places, angular, and aspecting, the native is a king or prince; when not all are angular but at least one is, a duke or great prince; when they are cadent and peregrine, a middling householder; and when no such bodyguarding holds, the native is 'of low-class people, of no memory.'
In Practice
Fix the sect first. In a day chart, look for the diurnal planets rising oriental of the Sun; in a night chart, for the nocturnal planets occidental of the Moon — the planets that attend the luminary of the sect. Then weigh how strongly they guard it: are they in their own domiciles or exaltations, do they sit on the angles, and do they aspect one another and the luminary? The fuller these conditions, the higher the rank you judge — all the relevant planets dignified, angular, and mutually aspecting points to the highest eminence; one such planet angular points to a great but lesser station; all of them cadent and peregrine points to a middling life; and the absence of any bodyguarding points to obscurity. Read dusturiyyah alongside the other rank-tests 'Umar gives — the triplicity-lords of the sect-light counted by their distance from the angles, and the rising-and-falling fortune patterns — so that the eminence judgment rests on converging testimony rather than this one configuration alone.
Historical Origin
Dusturiyyah is set out by 'Umar al-Tabari in his Three Books on Nativities (Book III, on social status), drawing on Ptolemy's Tetrabiblos IV.3, with the doctrine ultimately traced through Rhetorius to Antiochus. It is preserved in Benjamin N. Dykes's Persian Nativities (Vol II, trans. from the Arabic), who explains the term's origin as Greek doryphoria ('bodyguarding') and the 'rightness' sense (dexteratio) from the planets that rise to the right of, or ahead of, the Sun.