Special stamp booklets 1 Mark posthorn with violet Hand stamp "sample" on the 1. And additional "new price 3,- DM" on the 1. And 4. cover side, inside 10 postage stamp blind fields in the size 1 with "sample" stamp, on the 3. cover side "arrival postmark BzwVw 2352 Prora" as well red registration number "279". The sample stamp booklet served the tutelage the production workers and Leader the post offices. To the besetment were these with the hand stamp the arrival postmark BzwVw Prora and registration number provided