Please correct me if I am wrong, but I believe the poster is referring mainly to Oberndorf Mauser's commercial style script on military actions, not codes. Their were a number of commercial 98K's built primarily in 1933 and 34, such as the Postreich post office guns, railroad guns, gun club guns, and commercial exports that went all over the world, even the U.S. These usually had commercial proof marks. The ones that made it here were usually stamped "Made in Germany" on the floor plate. This was part of the Nazi's backdoor attempt at circumventing the treaty of Versai before they decided to just ignore it altogether. These rifles usually had a banner by itself on the the top of the front ring, or a banner with a date under it. The left receiver wall would usually say "Standard Modell", or "Mauser Werke A.G. Oberndorf a.n. Neckar" or something similar. Many commercial actions (mostly pre-WWI) were sold to the gunmaking/gunsmithing trade. These had the serial numbers on the bottom of the action behind the recoil lug and on the back of the magazine box like found on Mauser's commercial sporting rifles, but did not usually have any other reference in script to Mauser on the outside of the action. A few south American contracts used the intermediate commercial style action, such as the 1933 Buenos Aires Police guns, 1935 Chilean's etc. This is a long and large ring small thread intermediate action similar, and possibly identical to, the action used on most of J. Rigby's 275 rifles. The 1903 Turk and 1909 peruvian are very similar, but for the high clip notch and round bottom thumb cut (The commercial intermediates like this have a flat bottom thumb cut out. I won't say always because you never know what could turn up. The 1935 Chilean action is identical to the Commercial intermediate, except for markings.) I highly recommend John Speeds books on Mausers and "Mauser Bolt Rifles" by Ludwig Olsen. Brownells has is on sale for $19.95 right now. Wow! These books have more esoteric info about Mausers than one can possibly imagine.