25 drx (24.8.1915) in black on red and blue unpt with "Portrait of G. Stavros" at left and "Arms of King George I" at right. Digamma serial no "FΓ 829142 ωρ". Digamma is an ancient Greek letter similar to latin letter "F". Three ancient letters were used in 1903 and 1909-1918 issues of 25drx. Signature by Zaimis. Printed by ABNC. Inside plastic folder by PMG "Very Fine 20 - Digamma". (Pick 52a) & (Stratoudakis / Pitidis 51a).