SLAWIKAU 9.4.1921 single circle (326.1) on cover with single franking 40 Pfg green olive postage stamps issue 1920 to Regensburg, the letter was insufficiently paid and at the Regensburg 2 post office charged additional postage: single circle postage cleared / PA / REGENSBURG 2 / BHF a and manuscript notation 40 with blue pencil, signs of transportation