It can be confusing.
SureFire changed from "voltage" based numbers 3P for one-SF123A (3V) 6P/6Z for two-SF123A (6V), 9P/9Z for three-SF123A (9V) style model numbering, to flashlight-family or 'Series' based numbering. First it was C2/C3, D2/D3, Z2/Z3, M1/M2/M3 etc where the number indicted the number of SF123As, then SureFire changed again with the "L-Series" which were based on the LED bezel more or less. L4 used the KL4, L5 used the KL5, L6 (KL6), L7 (KL7) [which was out of keeping with the L1 and L2, and there was no L3 using the KL3]
Voltage-based nomenclature is also the basis for Classic WeaponLights. WeaponLight nomenclature has always been far more complicated (and therefore fun).
And now SureFire have mostly transitioned to a multi-alphanumeric model nomenclature, especially given their transition from incandescent to LED lights.
First it was the LED versions of existing models: A2L, 6PL, G2ZL are the LED versions of A2, 6P and G2Z.
And now that SureFire have transitioned to models which tend not to have removable bezels, the model numbering changes again.
These "Generation X" versions of well-known models: 6PX, G2X etc still hark back to classic model nomenclature given that the 6P is SureFire's Classic model.
The rechargeables have been named (numbered) using the "inbetween" numbers but again there were exceptions all over the place!
7Z (dedicated Z-Series version of the 6R), 8-Series (8X, 8AX, 8NX, L7), 9-Series (9N, 9AN) (could also be called the N-Series but never seems to be, probably because there was effectively only one model at a time so not much of a family!), 10-Series (10X, M1000/M2000).
I think that SureFire 'gave up' sticking rigidly to nomenclature canon almost as soon as they started as exceptions abound.
Of course with SureFire's proposed new rechargeables they have taken a new approach to model numbering where the "U" indicates a selector-dial type flashlight, and "R" indicates rechargeable with middle letter indicating the 'variant'
UAR "Aviator" (the Aviator ("A-Series") family with the A2, A2L, AZ2)
UBR "Invictus" (new Invictus ("B-Series") family along with the UB3T and never-released UB2/UB3 proto-types)
UDR "Dominator" (the Dominator family with the 10X Dominator)
UNR "Commander" (the new version of the 9N/9AN Commander)