I understand that Marlin started using that Trademark in their walnut-stocked guns in the early 1920's. It is not for the mounting of a sling swivel stud. It only goes in about a 1/4-1/2", and it will come out.
Thank you techhardt! I knew that post existed, and had read that in Brophy’s book, but was at my office and didn’t have either available at the moment. And yes, I do browse the forum at my office occasionally, but I’m the boss...and would never scold an employee for doing the same fine reading! Haha!