French Hallmarks Explained . . .
In France as early as the pre 1790’s silver objects had maker's marks. Additionally, they had marks identifying silver content, community/city of origin, tax status and inventory order. The tax status consisted of a charge mark (placed during production after the maker's and community marks) as well as a discharge mark (placed after taxes' payment.) These marks were regulated by the local assay office and so serve to identify origin also.

1798-1809 950 guarantie:     Paris  Paris Provinces  

Pre-1970's marks vary by silver content, assay office, date and whether item was large or small. This means that their number runs into thousands and to this day not all of them have been reliably ascertained. 

Post 1790’s the testing of silver content was taken over by the state. After this, fineness was indicated by the revenue tax payment mark a.k.a. poinçon de garantie.  From 1838 to 1972 French silver had four poinçons de garantie for two content levels (French 950 (95% silver) and French 800 (80% silver) and two article sizes, large and small.

 Large 950

 Large 800

             Small 800

  

crab   or    wart hog. 

 

In 1838, it was degreed that maker's marks must appear within a lozenge about 1/8" wide. They generally consist of the maker's initials and a symbol. This is the most reliable mark to use for dating purposes as the marks were registered with the local assay office and many of those records have been published.
 

In 1838, bigornes were instituted as a countermark on the opposite side of the guarantie hallmark. These are comprised of various insects engraved in relief and assembled by bands separated by molded borders.  This countermark became as important for determining fraud as the hallmark. The French also used special marks to denote imported or exported items. 
In 1973, the French silver standard was lowered to 925. The surrounds of the Minerve are the same, but a block letter indicating decade of manufacture (e.g., A for 1973-1982) appears in front of her neck and the "1" appears at the back  of her neck.  The boar's head was eliminated. 

International Hallmarks on Silver collected by Tardy, 1985