“They also devised an ingeniously low-tech solution to a complex problem. Even highly verbal autistic adults occasionally struggle with processing and producing speech, particularly in the chaotic and generally overwhelming atmosphere of a conference. By providing attendees with name-tag holders and pieces of paper that were red on one side and yellow on the other, they enabled Autistics to communicate their needs and desires without having to articulate them in the pressure of the moment. The red side facing out signified, "Nobody should try to interact with me," while the yellow side meant, "Only people I already know should interact with me, not strangers." (Green badges were added later to signify, "I want to interact but am having trouble initiating, so please initiate an interaction with me.") These color-coded "interaction signal badges" turned out to be so useful that they have since been widely adopted at autistic-run events all over the world, and name-tag labels similar to Autreat ("autistic retreat") green badges have recently been employed at conferences for Perl programmers to indicate that the wearer is open to spontaneous social approaches.”