The straight-line cached "GEZUIVERD" (cleaned) was applied to letters at the following purification offices in the Netherlands:
Arnheim (September 1831 to August 1832): the border post office for Prussian mail and frontier office for mail from France
Deventer (October 1831 to April 1832): the border post office for Bremen, Hamburg and Hannover
Winschoten (1831): the frontier with East Friesland
Brielle (February 1832 to July 1832): the "frontier office" for the English Packet service for Harwich
Hellevoetsluis (March 1832 to ? 1832): Naval quarantine station