The Ohio libraries tackled this problem first. A lilac OPLIN label says the bearer is an adult who has met all the requirements of the library to surf the Internet. A yellow OPLIN label identifies a minor whose parents or guardian has completed & returned all written requirements for the bearer to surf the Internet.
Libraries all over the world can use our WEB SURFER labels, filtered, or unfiltered, as they see fit.
A similar arangement for the other 49 states is accomplished with the different colors of 'web-surfer' labels for ID cards & keytags.