Use this tab to modify editable attributes of a pre-installed unit of measure and indicate all units with which you want to work. About 300 of the most common units from the international ISO Code lists ISO 31, ISO 1000, and ISO 2955 are preinstalled and available to select for use. You cannot enter any new units in this window. If you want to enter user-defined units, you can do that in the Units of Measure window.