Abstract: A simple, inexpensive labeling system for building conduit systems has a series of color-coded identifier tags that identify pipes, tubes, conduits, and the handles of various shutoff or control valves. Necessary emergency repair numbers, advertising, and an area for additional hand-written information may be provided. The identifier tags are die cut from durable, water resistant plastic and are of a sufficient thickness to provide rigidity to hang securely on pipes from a center hole and V-notch connected by a split. The user slips the identifier tag over the pipe by opening the notch and secures it by letting the notch close itself around the pipe.