All of Rick's knives were "customs" (up until the Gen 3 XM-18 with the production blade in 2008) but you never referred to them that way as it was obvious they were all customs and you didn't have to distinguish as there were no production blades.
As Rick put it back in May of 2008 to address the question of production versus custom when he first had some of the Gen 3 XM-18 3.5" blades CNC machined:
Guys! The XM-18 is still made in my shop by my hands! Just like before..The ONLY thing different is that I send the blade out to have it ground. I still mill it to shape and all just like before. All the hardware is still made by me in my shop.
I decided to send the blades out for grinding because there was no possible way for me to grind all the blades I needed to grind to keep up with the demand from those that wanted to use the XM-18 including a large bunch of military and law enforcement guys and gals.
I designed the XM-18 as a USING knife. Its great that people want to collect them but first and foremost to me is that it is to be used, and having a large bunch of our soldiers wanting my knife to help guarantee my freedom is what pushes me!
I have not forgotten about the collectors though! I will be grinding blades in my shop for a very limited number of XM-18's but only when I have the time to. And these will most likely be for the shows.
Thanks for all your interest in my XM-18!
And here is more info he posted in 2010:
what is the difference between my "production" and my "custom" XM-18?
The ONLY difference between the two is that the "custom" one is handground by me on my 2-72 belt grinder and the "production" one is ground on a cnc blade grinder at another facility...that is the ONLY difference.......everything else including the handles, hardware,screws,ect is made by us here in the shop, on the "production" XM's..How we build these knives by our hands is the same...and I say "our" hands meaning both Rob's that work for Rick Hinderer Knives also help build knives under my close (and I mean close) watchful eyes! However each and every knife including the "production" XM-18's go through my hands...if Rob puts it together I still closely inspect it and of course I sharpen each knife...
Now why did I pick the term "Production" for my Gen III XM-18 instead of "Mid-Tech"...because I dont like the term Mid-tech....since the time Ken Onion coined the term for his mid-tech Boa model this term has been twisted around so much that it no longer means what Ken intended it to mean...so I decided to call the Gen III a "production" build to seperate it from the handground XM-18's that are my "Custom"....That is it....even though the "production" XM-18 is more in the sence a "semi-custom" we still call it a "production" build...only because I wont attach the term "mid-tech" to it. But make no mistake these knives are built right here in my shop the same way I build my Custom XM-18's. Maybe the term "production" is not a good term describing the Gen III XM-18 but I thought it was the best term at the time...
There you go, the maker refers to them as "customs" and "productions" to distinguish them, that works for me.