The ecliptic point at right ascension RAMC + 90°: the ascendant at latitude 0.
Walter Koch's: the ascendant for RAMC + 180° at the latitude, plus 180°.
Michael Munkasey's: the ascendant for the RAMC at the colatitude.
Michael Munkasey's polar ascendant: the ascendant for RAMC + 180° at the latitude.
The four points of Swiss Ephemeris's
ascmc[4]toascmc[7], degrees in [0, 360).