The problem with trees Many systems are organized hierarchically. The CERNDOC documentation system is an example, as is the Unix file system, and the VMS/HELP system. A tree has the practical advantage of giving every node a unique name. However, it does not allow the system to model the real world. For example, in a hierarchical HELP system such as VMS/HELP, one often gets to a lead on a tree such as: HELP COMPILER SOURCE_FORMAT PRAGMAS DEFAULTS only to find a reference to another leaf: Please see HELP COMPILER COMMAND OPTIONS DEFAULTS PRAGMAS and it is necessary to leave the system and re-enter it. What was needed was a link from one node to another, because in this case the information was not naturally organized into a tree. Tim Berners-Lee, Seeing With Fresh Eyes A City Is Not a Tree hierarchywww
Cool URIs don't change An Essay by Tim Berners-Lee www.w3.org What makes a cool URI? A cool URI is one which does not change. What sorts of URI change? URIs don't change: people change them. The User Interface of URLs www
A state of energetic repose Read the text before designing it. Discover the outer logic of the typography in the inner logic of the text. Make the visible relationship between the text and other elements (photographs, captions, tables, diagrams, notes) a reflection of their real relationship. Give full typographic attention even to incidental details. Invite the reader into the text. Reveal the tenor and meaning of the text. Clarify the structure and the order of the text. Link the text with other existing elements. Induce a state of energetic repose, which is the ideal condition for reading. Robert Bringhurst, The Elements of Typographic Style The inner nature of material typography