IEEE Std 260.1-2004
IEEE Standard IEEE Std 260.1-2004 provides standard letter symbols for units of measurement for use in all applications in multiple contexts. It covers primarily SI units and customary inch–pound units. The symbols are sorted in alphabetical order of name from ampere (symbol A) to zetta (symbol Z), including barrel (symbol bbl), bit (symbol b), foot (symbol ft), kibibyte (symbol KiB) kilowatthour (symbol kWh), microinch (symbol μin), quart (symbol qt), slug (symbol slug) and year (symbol a). In some cases the same symbol is used for different units. Examples are the symbols B (for bel and byte), Gb (for gigabit and gilbert), L (for liter and lambert) and rad (for rad and radian).