Proofmarks
Most countries proof their firearms. When the arm passes the test a proofmark is punched on vital parts (Duits: Beschußzeichen, French: Poinçon). On this page you'll see some Belgian proofmarks. The Belgian proofing institute is situated in Luik (Banc d'épreuve des armes à feu). Due to a fire in 1922 all the archives of inspectors were lost resulting in the fact that punches applied before 1922 can't be traced back to the applying inspector or the date the arm was punched. More proofmarks: http://www.proefbankstempels.nl/
POINCON

Punches from the Belgian proofauthority (Luik)

stempelsatz

Punches from the German proofauthority (Ulm)

Gewöhnliche Ladung

Proofmark (normal testload)

Verstärkte Ladung

Proofmark (extra load)

Verstärkter Beschuss

Proofmark (Poudre Vive; smokeless)

Zusätzliches Zeichen für den rauchlosen Endbeschuss

Proofmark smokeless powder (excessive pressure 50%)

Endbeschuss mit Schwarzpulve

Proofmarks for black powder. "R" stands for Rifled barrel (Rayé)

ausländische Waffen, die in Belgien beschossen werden

Belgian proofmark for foreign arms

Freiwilliger Beschuss

Voluntary proofed

be12

Proofmark (A..Z) from 30-12-1853 till 26-01-1877

be11

Proofmark from 27-01-1877 till 26-02-1968