The German designations of foreign firearms in World War II is a list of known foreign firearms and equipment compiled by the German armed forces before World War II.
The purpose of these lists are threefold: Before the war began the German armed forces Heereswaffenamt compiled a list of known foreign equipment and assigned a unique number to each weapon.
The Germans also captured large amounts of foreign equipment during WWII (for example, over 11 million rifles by the end of 1944[1]) that they tested and cataloged using the same system.
In practice common model designations don't always share the same ID numbers.
Also while a Mauser model 98 from different countries may be able to fire the same ammunition that doesn't mean their parts are compatible or interchangeable.