GS1 Guidance for Marking Technology by Substrate Type • GS1 provides direct marking guidance in the GS1 DataMatrix Guideline and Table 7 of the GS1 General Specifications • FDA does not state marking method to use, mark must last the expected service life of the device • GS1 refers to ISO/IEC TR 29158 as the relevant reference specification for direct part marking • GS1 DataMatrix and GS1 QR are the only allowed symbologies for direct marking • GS1 recommends that GTIN and serial number be included in the direct mark. Sources: GS1 2018 General Specification and GS1 DataMatrix Guideline, v. 2.5.1, January 2018