When would you use profile of a surface tolerance instead of other GD&T controls?

Profile of a surface is used when controlling complex contoured surfaces that cannot be defined by basic dimensions and traditional tolerances. It establishes a uniform tolerance zone around the true profile defined by basic dimensions. Applications include aerodynamic surfaces, cam profiles, injection molded parts, and complex castings. Profile can control form, orientation, and location depending on datum references specified, making it versatile for complex geometry.