Movie hoods

I was trying to understand what the hell meant the letters I. their masks, in the torsos says their elements bit for Jay says SPARK instead of lightning (probably because is too large) and for Lloyd says NINJA. Bit in the headbands I don't understand the logic Cole: E (for earth) Nya: W (for water) Kai: H (WHY NOT "F", buy I think that is probably for heat or something like that) Lloyd: LL (at first I don't understand what does it says but then I realized that is a double L for Lloyd Zane:...