This document was updated in February 1995. It defined the characteristics of the serial time code formats A, B, D, E, G, and H. The task of revising this standard was assigned to the Telecommunications and Timing Group of the Range Commanders Council. This 1998 edition of the document incorporates Manchester modulation for codes so designated. This standard should be adhered to by all U.S. Government ranges and facilities where serial time codes are generated for correlation of data with time