Domestic registered letter with perfin “Ph.G.” in the stamp. The letter is franked correctly with 2 x 20 + 5 øre = 25 øre, which was the rate for domestic letters in the period from March 1st 1921 to December 31th 1926 and 25 øre was the fee for registering. The stamp is cancelled August 21th 1926 with København K Nr. 201, København K25 Bro Vb. This is the prove for the earliest known use of this perfin.