Okay so today I was reading the patch note, when I've read this. Where I can find the damage type label ?
A lot about the resistance types for construction modules are not well understood or documented at the moment. Addiitonally, weapons do not necessarily have the same resist type after the 3 May 2016 update. You can use the 3 May 2016 notes the garner some details about how the "resist type #" notation works and how weapons were adjusted. For example, resist type 34 belonged to direct damage from the Decimator at the time of writing. (One thing to note is that the update only talks about "modules in general" for a resist type, not the specific resist type on which specifric module.)
I already knew this resistance chart but I think it wasn't updated since a lot of time. Thanks for the link of the 3 may patchnote, there aren't all the resist label but it's a start.
Seems I've found some source on Reddit about damage type label. Here is the list I could found. Resistance type 1 Melee (knife) Resistance type 2 Small weapon Resistance type 3 Light ordnance (direct fury, bulldog) Resistance type 4 HMG (basilisk) Resistance type 5 Medium ordnance (halberd / annihilator) Resistance type 6 Explosive splash Resistance type 7 Heavy Ordnance (HE, HEAT, Viper C75, dumbfire RL) Resistance type 8 Air MG (ESF nosegun) Resistance type 9 AV explosive (AV mine) Resistance type 11 C4 Resistance type 12 Flak burst Resistance type 15 TR sniper rifle Resistance type 18 Rocket pod direct Resistance type 19 Light flak direct Resistance type 20 NC sniper rifle Resistance type 21 VS sniper rifle Resistance type 22 AA HMG (walker) Resistance type 24 Lancer Resistance type 26 Phoenix Resistance type 27 AP Ordnance Resistance type 28 AP HMG (vulcan) Resistance type 29 Vortex 1 Resistance type 30 Vortex 2 Resistance type 31 Vortex 3 Resistance type 34 Decimator Resistance type 38 Striker
The one on my first post ? It's percentage. For example, when the devs said " Changed resist type 2 to 69 from 85 " That mean they've changed the item (it was a construction module if i remember right) resistance value to type 2 (witch is small weapon) to 69% resistance. So if a module have 500 HP with 69% resistance, you'll need 13 bullet of NS7-PDW (38.75 per bullet instaid of 125)