For some reason, Bob's naming scheme would often confuse people. It can be if you don't follow his work. Here's what I've come to understand of it, and what I use when I'm asked questions about his models:
Bob offers two classes of knives: One-off customs that follows a style/pattern, and his "Regulars".
The One-offs could be fashioned in any way, often determined by the customer who placed the order. And in the early to middle part of his career, most of the knives he made would fit into this category. These include Hunters, Skinners, Large Tanto's, Fighters, and his Armour Piercing Dagger (including the Americanize Tanto variant). This is also where Bob exercised his creativity with his tantos. They would come in any size, with multitudes of details and finishes.
His "Regular" offerings were his "Bread and Butter" models. In the later stage of his career, the naming scheme would apply more to his Folders than his Fixed Blades. Of his Fixed Blade offerings, he had a few models; Tanto, Stalker, Chinese Fighter, and Sabertip Fighter. Of his Folders they were many, among them; Chinese Folder, Folding Tanto, Folding Stalker, Folding Skinner, Folding Dagger, All-Rounder, Folding Tanto II, Forester, Two Bladed Folder, and others.
What differentiates his models are the handle treatments. Bob's low end models were always the Field Grade ones. These usually were handled with Micarta, G10 or Carbon Fiber, and in plain Titanium for his Folders. The other range is the Deluxe models. These will include wood and other natural materials for handles (the most popular choice being Stag), and would very often have bolster treatment(s).
Regular models have one additional variation: they come in several sizes. Small, Medium, and Large. For Fixed Blades, Small came with a 3" blade; Medium with a 4" Blade; and Large with a 5" Blade. For Folders, Small came with a 2" Blade; Medium, a 3" blade; Large, a 4" Blade. Some Folders also came in an XL size with a 5" Blade.
Hopefully this has helped demystify Bob's offerings. If not, and you have one of Bob's knives that you're not sure which model it is, I would be more than happy to help you sort it out. Just email me some pictures of the knife.