Each Belgian Stamp (including those stamps printed with belgain postal face value for the United Nations) is also been issued in a black and white proof sheet with dry cancellation of the Belgian Post. There are only 23 copies of this proof stamps. These sheets are known as Ministerial Sheets since only Ministers of the Belgian Government were entitled to get them. Below are these shown in 'photo' quality since in scanned format, you cannot depict the dry cancellation of the Postal Authorities.

Ministerial sheets are hard to get. Since the United Nations philatelic items falls under a separate thematic, those of the United Nations are even more hard to get.

Below you will only see the 10 first ministerial sheets as well as one out of the serie of the airmail stamps (remaining hopefully soon to come).

The only ministerial sheet of the airmail serie: