The Book of Unwritten Rules Young people who hang out on street corners and in parks turn public space into their own private domain. Usually this is seen as a problem. Apparently, creating a private space in public is not permissible. But are there definable limits to private and public space? When is it permissible to have a private domain in public? Is there a link between the people who complain about loitering youths and the youths themselves? These questions are only indirectly related to issues of space or safety. Primarily they have to do with written and unwritten rules, rules that apply not only to loitering youths but also to others who claim their own spot in a public space − by planting a sidewalk garden, for example, or turning the sidewalk into a private patio. Unwritten rules are often more important than written ones; they form the basis for making claims on public space. The interesting thing about these unwritten rules is the way they are applied. The Book of Unwritten Rules is a search for new unwritten rules. The search involves developing methods not only for finding these rules but also for encouraging open discussion of them.  Discussing unwritten rules is more difficult than discussing written ones, but it provides important insight into the utopian ideas of certain population groups, about how they touch each other and come into conflict with each other. So describing something that is unwritten is not a paradox but an instrument for arriving at new ideas about living together and about the apparent contradiction of private space in the public domain.