What is shown in the legend of a plumbing blueprint?

The legend of a plumbing blueprint is essential because it provides a clear key that translates the various symbols and drawings represented in the plan. This includes symbols for fixtures like sinks, toilets, and bathtubs, as well as piping, valves, and other plumbing components essential for understanding the setup and flow of the plumbing system.

Having a well-defined legend ensures that anyone reading the blueprint can accurately interpret the various elements without confusion, making it a crucial part of the document. While the other options contain important information that might appear in different sections of the blueprint or additional documents, they do not pertain specifically to what the legend encompasses. The legend's primary role is to demystify the symbols associated with plumbing components, ensuring that contractors, installers, or inspectors can identify and work with the necessary plumbing features effectively.