1906, postal matter / acknowledgments of receipts: registered, post paid postal matter for 3 acknowledgments of receipts with the numbers 284, 286 and 299 with clear posting stamp HERBERTSHÖHE DNG 28 / 11 06 to Leipzig. There was the complete cover to the consignee Albert Friedemann forwarded. Reverse blue paper seal "Emperor. German letter post office Leipzig 13". Signed Friedemann. Those covers are very rare