Is headwear restricted by NFHS?
 

Fellow officials:

I've been through the books a time or two and cannot find any NFHS rule restricting the wearing of any headwear under the football helmet. The only thing I thought I heard once was the idea of wearing a bandana and that if part of the bandana stuck out from underneath the helmet, that would be illegal. Would you please advise on the legality of wearing something under the helmet? If you know it is illegal, please let me know where to find it. I know of no state restrictions that apply to this rule in the state of Iowa, where I work. Thanks.

If seen outside the helmet, it becomes or falls under the adornment rule.
Otherwise, it's not an issue.

That being said, I have heard of some places that make the wearing of this device illegal because of "gang" association. That's a different issue and I have no complaint about it.

The previous supervisor in NC made it illegal here
 

for two reasons- 1) potential gang affiliation and 2) the tying of the bandana creates a knot which creates a protrusion into the helmet, thus a safety issue to the player. If seen, it was considered to be uniform adornment.

The new, knit, skullies by Nike, UA , et al are deemed ok.

Illegal in KS. Safety issue. Helmets are designed to fit snuggly on the head. Anything that interferes with that fit could cause injury. Knits, scullies nothing can be worn under the helmet.