Howdy!
The 2-letter designators for the Strider models are, in a word, OPSEC. However, I can tell you that each one is chosen for a specific reason. Some are named after certain events that occurred during the design or construction of the knife, and others are named after fellow warriors, some living, and some not.
The bottom line is, though, that if you have to dump someone's guts with one during a confrontation, you'd be better off defending yourself in court with an "HT", rather than a "Phantom Spine Slasher From Hell". Quiet professionalism is the mode we operate in, and as you well know, the blades speak for themselves.
Hope I've been helpful. Rattle my cage if you have any more questions.