Syria, Seleucid Empire, Antiochos VIII Epiphanes (Grypon) Tetradrachm, 109-96 BCE Antioch Mint. Obv. Diademed head of Antiochos VIII right / Rev. Zeus Nikephoros seated left on high-backed throne, holding Nike on outstretched right hand and scepter in left; to outer left, P/E monogram above A; ΔI monogram below throne; BAΣΙΛΕΩΣ ANTIOXOY EΠIΦANOYΣ; all within laurel wreath. Seleucid Coins [SC] Pt. 2, 2309; Seleucid Coins Online [same] (see http://numismatics.org/sco/id/sc.1.2309); Seaby 7145 (ill.) [D. Sear, Greek Coins & their Values, Vol. II: Asia & Africa (Seaby 1979)]; Hoover HGC 9, 1200 [Oliver Hoover, Handbook of Syrian Coins, Royal and Civic Issues, Fourth to First Centuries BC, The Handbook of Greek Coinage Series, Volume 9 (2009)]; Newell SMA 405 [E.T. Newell, The Seleucid Mint of Antioch (1918)], SNG Israel 2554-55 [A. Spaer & A. Houghton, Sylloge Nummorum Graecorum, Israel I, The Arnold Spaer Collection of Seleucid Coins (London, 1998)]; BMC Seleucid Syria 2 (p. 98) (ill. Pl. XXVI, No. 3) [erroneously attributed to Antiochos XI] [P. Gardner, A Catalog of the Greek Coins in the British Museum, Vol. 4, The Seleucid Kings of Syria (London, 1878)]. 27 mm., 16.2 g. (Purchased from Frank S. Robinson in Feb. 2020 auction.) Here are closeups of the two monograms: The P/E above A, on the left: The ΔI monogram below the throne: These same two monograms appear on most of the examples of this coin type shown at Seleucid Coins Online (http://numismatics.org/sco/id/sc.1.2309). They also appear on the British Museum's example on Plate XXVI of its 1878 catalog volume entitled The Seleucid Kings of Syria (for whatever reason, erroneously attributing the coin to Antiochos XI): Does anyone have any idea what either of these two monograms signifies?