This metric practice guide is based on the International System of Units (SI) as defined in the U.S. Federal Register notice of July 28, 1998, "Metric System of Measurement: Interpretation of the International System of Units for the United States." It includes the base units, derived units, and rules for their use. Also covered are conversion factors and rules for their use in converting inch-pound units to SI units. Recommendations are presented for style and usage in such areas as prefixes, punctuation, number grouping, etc. There are also suggestions to industry for managing the transition.