Why are bookmarks always one-dimensio­nal? In a row like pearls on a string. They are organized alphabetically or chronolo­gically, but almost never in a meaningful way. It is an obvious idea to organise the information on a surface (like parts of a puzzle), which allows the simultaneous organization according to different crite­ria. Pretty simple, right? Very sensual and very meaningful. ‘Sinnzeug’ is more than just a list of bookmarks. ‘Sinnzeug’ esta­blishes a principle. An ingenious principle.