This standard presents a mathematical definition of geometrical dimensioning and tolerancing (GD&T)consistent with the principles and practices of ASME Y14.5m-1994, enabling determination of actual values. While the general format of this standard parallels that of ASME Y14.5m-1994, the latter document should be consulted for practices relating to dimensioning and tolerancing for use on engineering drawings and in related documentation. Textual references are included throughout this standard which are direct quotations from ASME Y14.5m-1994. All such quotations are identified by italicized type. Any direct references to other documents are identified by an immediate citation. The definitions established in this standard apply to product specifications in any representation, including drawings, electronic exchange formats, or data bases. When reference is made in this standard to a part drawing, it applies to any form of product specification.