SI Unit Prefixes

Any unit may have an SI unit prefix preceding it which can be applied either directly (as in hectogramme) or with an intervening underscore (hecto_gramme).

Unlike the units themselves the SI prefix cannot be abbreviated as it would introduce too much syntax ambiguity.

Many standard units actually incorporate the SI prefix in them (mm, cm, kg) these are still standard units so it is actually (although misleadingly) possible to duplicate this as in millikg (which is, equivalent to a gram).

The system does not forbid use of SI prefixes with imperial units, although, this is not to be encouraged.

The set of prefixes supported are: