This standard defines uniform quality and technical requirements relative to metallic parts marking performed using ??data matrix symbology?? within the aviation@ space@ and defence industry. ISO/IEC 16022 specifies general requirements (e. g.@ data character encodation@ error correction rules@ decoding algorithm). In addition to ISO/IEC 16022 specification@ part identification with such symbology is subject to the requirements in this standard to ensure electronic reading of the symbol. The marking processes covered by this standard are as follows: ? Dot Peening; ? Laser; ? Electro-Chemical Etching. Further marking processes will be included@ if required. Unless specified otherwise in the contractual business relationship@ the company responsible for the design of the part shall determine the location of the data matrix marking. Symbol position should allow optimum illumination from all sides for readability. This standard does not specify information to be encoded. Convention The following conventions are used in this standard: ? The word ??shall?? indicates mandatory requirements; ? The word ??should?? indicates requirements with some flexibility allowed in compliance methodology. Producers choosing other approaches to satisfy a ??should?? shall be able to show that their approach meets the intent of the standard??s requirement; ? The words ??typical??@ ??example??@ ??for reference?? or ??e. g.?? indicate suggestions given for guidance only; ? Appendices to this document are for information only and are provided for use as guidelines; ? Dimensions used in this document are as follows. Metric millimetre (mm) sizes followed by inches (in) in parentheses@ unless otherwise stated.