The roll mark is the "Mauser Banner" regardless whether its a military or commercial rifle or pistol.
Mauser used the term Stand.-Gewehr in sales ledgers, and then Gewehre & Karab. after 1933.
Mauser did not use the "Mauser Banner" description. In correspondence, the terms Mauser Standard-Gewehr
and Mauser-Gewehr fur Deutsche Reichspost were used. You see the variability here.
The term "Banner K" is a collector used term to identify all of the varieties of the Banner rifles, these being issue to the following organizations:
Reichsbahn, Reichspost, ChdA, and Gr.B.B
This is all detailed in Volume I.