I wanted to see if someone could help me out. I got this 1912 Enfield from my dad. I have figured out most of the markings through internet searches but one of them continues to elude me. On the left hand side below where the safty would be is a marking. It is an arrow pointing up with RIF and 1927 below it. Any thoughts on what this is? https://www.milsurps.com/images/impo...IMAG2969-1.jpg