This is one of those B'Rel offshoots that has it's own class name - apparently in the same naming structure as the original D-7 battlecruiser from TOS. Under this scheme some have suggested that the K'T'Inga class is actually a D-9; if so, it is possible that these schemes run together and that ships like the Vor'Cha and Negh'Var also have such numbers. One strong possibility is that the Klingons give their ships proper Klingon names, and that the letter-number designation is the Federation code for the ship - much as NATO gives code names such as Flanker or Fulcrum to Russian fighters even though they have their own Russian language type names. However, since that's pretty speculative I've just stuck with the names we've been given on screen, no matter what format they are in.

The history of the D-12 is my own invention, as is the names of the ships involved in accidents. I'm no Klingon language expert, and I have no idea if Javakorr, Kolnar and Nak'Leth are real Klingon words. One of them - Nak'Leth - I picked because it had the same end as Bat'leth and Mek'leth. If anybody is interested, I imagine the Nak'Leth to be the Klingon version of a battle-axe - something huge and very heavy.

The ultimate fate of the D-12's was described - briefly - by Worf in Generations, during the attack on the E-D. The fact that an entire ship class was retired from service because a single system was vulnerable to ionic pulses is a pretty clear indicator that most Trek ships would be highly resistant to such effects. The details surrounding the faults in the design are entirely my own.