Hi popcornpicker,
I've noticed you've had a few questions regarding lights for your son in service lately. First of all, thanks to him for his service and you for supporting him.
I thought you might find the
Approved Family of Flashlights list (AFFL) interesting. It is not, to my knowledge, a codified requirement where other flashlights are not permitted, but rather a helpful guide. Who knows how that might swing in the future. It was put together by the Army, but I'd imagine the recommendations and selection criteria could be helpful for any branch of the Armed Services. They note that the Marines are fielding a similar program.
The selection criteria are discussed
in this thread.
You'll notice that they list the Surefire helmet light as an approved light. This certainly means that the Army approves of at least certain headlamps.
As noted by other posters, I think the issue is just mission specificity. In a secure area where tasks need to be carried out, a headlamp would be great as it would offer him hands-free lighting. Out on a roving patrol however, if he just left it on, it would indeed be a target.
A headlamp would presumably fall under all the same light discipline guidelines as a hand held light within his unit. The difference being that it is generally quicker and easier to switch off a hand held light (or at least quickly cover it) than a headlamp if the need to go dark suddenly arises.
Best of luck to him and safe return home. I'm sure he'll appreciate the kit you're sending his way.