Single franking of 1 Mark Imperial Post Office, dark carmine-red, wartime printing, perforation 25:16 holes, watermark 1, on official form C130IIa, cancelled with bridge datestamp "Kreuztal * (Kr. Siegen) * -6.5.20 4-5N" plus pen signature on stamp, declaration by Berlinger Walzwerk GmbH to the Imperial Post Office Krombach concerning collection of mail, including official authentication of signature in lower part. Stamp acknowledges the accounting fee for issuing the collection declaration. Form in age-typical condition, slightly trimmed at top and bottom, folded horizontally and vertically, small tears and creases. Very few such items are recorded in the literature, as they normally remained in postal files and were destroyed after the retention period. Detailed expert report Claudius Kroschel VP (2025) "Stamp has fresh colour...in sound used condition"