This Annex comprises the Standards and Recommended Practices for dimensional units to be used in air and ground operations. The Annex deals with the standard application of units of measurement and termination of the use of non-SI units. Attachments to the Annex contain material describing the development of the International System of Units (SI) and guidance on the application of the SI, conversion factors, Coordinated Universal Time (UTC), and presentation of date and time in all-numeric form.