All About Pocket Knives

I can't quite find anything like this in my sheath guide which may be limited- i think i have it dated to the xx period, but i can't find the pattern- it has that grooved serrated edge or whatever on the side not smooth all the way down- obviously it's been used and sharpened- thanks in advance also my book has stampings of different letters where would those stampings be located on a sheath knife?-- such as L, D, J etc?