This guide was designed to provide a measure of uniformity across Canada with respect to metric terminology and symbolism, and is designed to enable users to understand and apply Systeme International d'Unites (SI) to everyday life with ease and confidence. This document was written with the intent of being helpful to the greatest number of individuals in the education sector, as well as the general public. It deals with the correct style to be used in expressing metric terms, units of measure, and their symbols, but does not cover the teaching of the metric system. There are three main parts. Part A deals with common everyday units, a few simple related features of these units, and some fundamental rules of style. Part B outlines the structure of SI and gives a further extension of rules of style. The last part includes tables of metric units, definitions, and other terms of a reference nature. A comprehensive index completes the document. (MP)