People have been saying
Armor level = 1
Others say it is the SOFT tag
But personally, SOFT was for older versions and I think only controls if the clothes can be made from CLOTH or THREAD like materials
LEATHER well leather, and HARD for hard materials? Materials with ITEMS_HARD i guess.
ARMORLEVEL:1 will stop wear, but at teh cost of it counting as ARMOR so naked embarks are a go. And civvies must be told to wear them (I think some have said this, others say embark team is naked but will wear clothes that are made, and migrants come clothed?)
Cue Putnam.
This is a touchy subject.
Toady actually said that chainmail is xounted as clothing now, which has armorlevel. The change made it from LAYER:ARMOR into LAYER:OVER. I guess it is that makes it into clothes now and reduce negative thoughts - that it is not ARMOR layer. Need to try to take out all shirts and robes and see if dwarfes start wearing chainmails:)