What do the markings on the barrel of my 870 mean?

[Rabbit]

Hello Forum,
I recently picked up a copy of The Gun Digest book of the Remington 870 by Nick Hahn. I wanted to share a few pictures that showed some of the identification code stamps found on 870 barrels and what they mean.
Rabbit

[Synchronizor]

Good info, thanks for sharing it.

I would add that not all 870 barrels will have all of these markings. There have been changes over the years, and certain types of barrels (especially LE/military vs. civilian parts) may be marked differently even if they were made around the same time.

[mhuisman]

I am trying to find out some information on an 870 Wing Master. I was looking at the marks on the left side of the barrel. Are there mulitple "Final Inspector" marks? The one on mine doesn't look like the one in the drawing. Secondly, I don't see anything that looks like a serial number on the left side of the barrel, just the letters O R K. Is that all there was for S.N. s on these? I plugged the O and R into the decoder, and it spit out 1968. That year coincides with when I believe it was originally purchased. Any help is appreciate. Thank you.

[Synchronizor]

Barrels normally don't have serial numbers, that's on the gun's receiver. Vitaly really needs to fix the wording on that page.