Marking on my op rod catch

This op rod catch has an "X" stamped into it and I have never seen that before, does anybody know if it has any significance?

Thanks

Dan
https://www.milsurps.com/images/imported/deleted.gif

Dan, I've been informed that "letter codes" were indicative of IHC manufacture. I haven't broken out my new book by Larry Babcock, but maybe it is listed in there.

Thanks Gus

Dan