This marking can be seen on some Indian tulwars, kukris and gurdas. The origin is assumed to be European as some European (Italian) swords have such a mark. Do you know on any books on European swords and sabres that discuss this issue? If yes could you provide me with reference and page number please?

Kind regards
Manouchehr

I don't know about swords but as I recall they are referenced on various Italian pole arms specifically the beast known as a Roncone. I seem to recall reading that in John Waldman's Hafted Weapons in Medieval and Renaissance Europe. If I remember I'll see if I can dig up a page number for you tonight.