Anyone who cares about the earth and their fellow man is automatically a member. Ages vary from 1960´s flower power veterans to new-borns. The "Rainbow Family of Living Light", also known as the "Rainbow Family" is an international, non-hierarchical, non-organized, loose-knit group of hippies. At least in a flag! And hopefully in person. The symbolism being that all of the different peoples or tribes can come together in peace and harmony.
The stripes of many colors represent all of the tribes of the earth. The canton of stars represents all of the constellations - united, or the U.S. The Rainbow Family has used the "New Glory" flag for many years.
Also available was a Rainbow First Navy Jack before 1978. It is called "New Glory" and predated the "Gay Nation" rainbow by at least six years, probably longer. They were also made by Colors of the Wind in Santa Monica in the 1970's (I think theirs started with a purple stripe). It still is, and as they are quick to point out, "They had it first!". It was popular with the "Rainbow Children" and other similar counter culture groups. before 1978 and the subsequent adoption of the rainbow as a symbol of Gay Pride. These flags were a regular production item at the Paramount Flag Co.