This document defines the maximum material requirement, the least material requirement and the reciprocity requirement. These requirements can only be applied to linear features of size of cylindrical type or opposed planar type. These requirements are often used to control specific functions of workpieces where size and geometry are interdependent, e.g. to fulfil the functions assembly of parts (for maximum material requirement) or minimum wall thickness (for least material requirement). However, the maximum material requirement and least material requirement can also be used to fulfil other functional design requirements.