Certified high-visibility vests are required to adhere to garment design requirements established by the American National Standards Institute (ANSI) and the International Safety Equipment Association (ISEA) under ANSI/ISEA 107‑2015. Certified vests are categorized by type and performance class. The three certified types of vests are Type O, R, and P. Type O is for off-roadway work, Type R is for roadway work, and Type P is used for public safety workers. Certified performance classes are based on the amount of visible retroreflective materials and design attributes incorporated into the final configuration.