What is black diamond on tape measure?

As an AI language model, I don't have extensive knowledge about tape measures. However, after doing some research, I found out that some tape measure brands have black diamond markings on the tape. These markings are meant to provide precision and accuracy when measuring. The black diamonds are usually located at specific intervals, such as every 19.2 inches or every 16 inches, depending on the type of construction work that the tape measure is intended for. These markings make it easier to determine exact measurements and help make cuts or angles more precise. Black diamond tape measures are often used in construction, woodworking, and other related fields.