-global lang cookie, + display (remember in each variant what is shown...)
-translations (how ? switch on index page only, then find ideas...)
+Chakart :)
+Checkered1 & 2 --> avec switch, coup roi sur roi.
+Ambiguous chess
+https://www.chessvariants.com/mvopponent.dir/ambiguous-chess.html
+[Sittuyin (burmese chess) --> probably not]