In the world of hand made knives the term custom knife means that the knife is made by one guy one knife at a time. There is occasion where the maker has an apprentice and some times he sends some stuff out like heat treating, engraving or some thing that he does not want to do himself.
The creation of the knife is primarily in the idea and less so in the actual making of the knife. Design, steel type, individual heat treatment, intended purpose of the knife, particular grind etc. is determined by the customer and the maker.
I can agree with Hoss on that 100%, I just think the grey area is in the term "made". If I buy sheets of steel, have it waterjet cut, then grind it myself, then ship it with no handle, did I make it? Also, I don't think that anyone would argue that a Pierre Rodrigue knife with a Stefan Keller handle is not a custom.
It's just a vague term, and is not used to denote one specific group of things. There is a sense that it wasn't "manufactured", or created en-masse like an assembly line by several people(or robots). Other than that, I just think "one maker, one knife at a time". The more you farm jobs out, the less I consider it a custom(though that doesn't mean it's worse).
Collaborations are acceptable forms of custom knives, and they can be fun and exciting.
I dunno if we should accept Hoss' opinions on this.......................
"The Buddha resides as comfortably in the circuits of a digital computer or the gears of a cycle transmission as he does at the top of a mountain."
I move that Hoss should recuse himself.