Covertly communicate with your smartphone-wielding brethren. During the 19th and 20th centuries hobos (a wandering homeless worker) developed hobo codes, a system of marks made with chalk to help each other find useful opportunities and avoid danger. Golan Levin and Asa Foster III have updated this system for the digital generation with QR code stencils. They first developed the QR_STENCILER with Processing to automatically generate stencils of QR codes for laser cutting. The challenge with QR codes is that some of the elements are “islands.” There are parts without any connection to the edge, which is a problem for stencils. They adroitly solved this problem with thin connectors and rounded corners that are generated automatically and don’t interfere with reading the code. They then used this tool to create QR_HOBO_CODES for digital nomads. The basic idea is basically the same as the old hobo code, except that the code is read with a camera phone. In addition to some of the original codes, such as “food for work,” they have developed new markings specifically for digital culture, such as “free w-fi.”