What are hippie headbands called?

Originally head bands had a function; they kept their long hair out of the way. Then of course, it became a trademark; in Vietnam, the drafted Hippies found a new function for them (since their long hair had been cut when they were drafted)...head bands kept sweat out of the man's eyes. M-16 rifle bandolier straps were normally used to make head bands with. Sweat was a big problem in Vietnam.