simpleType {http://www.xml-cml.org/schema/stmml}unitsType

These will be linked to dictionaries of units with conversion information, using namespaced references (e.g. si:m)

Distinguish carefully from unitType which is an element describing a type of a unit in a unitList

<stm:unitList xmlns:stm="http://www.xml-cml.org/schema/stmml">
<!-- ======================================================================= -->
<!-- ========================= fundamental types =========================== -->
<!-- ======================================================================= -->
<stm:unitType id="length" name="length">
  <stm:dimension name="length" power="1"/>
</stm:unitType>
<stm:unitType id="time" name="time">
  <stm:dimension name="time" power="1"/>
</stm:unitType>
<!-- ... -->
<stm:unitType id="dimensionless" name="dimensionless">
  <stm:dimension name="dimensionless" power="1"/>
</stm:unitType>
<!-- ======================================================================= -->
<!-- ========================== derived types ============================== -->
<!-- ======================================================================= -->
<stm:unitType id="acceleration" name="acceleration">
  <stm:dimension name="length" power="1"/>
  <stm:dimension name="time" power="-2"/>
</stm:unitType>
<!-- ... -->
<!-- ======================================================================= -->
<!-- ====================== fundamental SI units =========================== -->
<!-- ======================================================================= -->
<stm:unit id="second" name="second" unitType="time">
  <stm:description>The SI unit of time</stm:description>
</stm:unit>
<stm:unit id="meter" name="meter" unitType="length"
  abbreviation="m">
  <stm:description>The SI unit of length</stm:description>
</stm:unit>
<!-- ... -->
<stm:unit id="kg" name="nameless" unitType="dimensionless"
  abbreviation="nodim">
  <stm:description>A fictitious parent for dimensionless units</stm:description>
</stm:unit>
<!-- ======================================================================= -->
<!-- ===================== derived SI units ================================ -->
<!-- ======================================================================= -->
<stm:unit id="newton" name="newton" unitType="force">
  <stm:description>The SI unit of force</stm:description>
</stm:unit>
<!-- ... -->
<!-- multiples of fundamental SI units -->
<stm:unit id="g" name="gram" unitType="mass"
  parentSI="kg"
  multiplierToSI="0.001"
  abbreviation="g">
  <stm:description>0.001 kg. </stm:description>
</stm:unit>
<stm:unit id="celsius" name="Celsius" parentSI="k"
  multiplierToSI="1"
  constantToSI="273.18">
  <stm:description><p>A common unit of temperature</p></stm:description>
</stm:unit>
<!-- fundamental non-SI units -->
<stm:unit id="inch" name="inch" parentSI="meter"
   abbreviation="in"
  multiplierToSI="0.0254" >
  <stm:description>An imperial measure of length</stm:description>
</stm:unit>
<!-- derived non-SI units -->
<stm:unit id="l" name="litre" unitType="volume"
   parentSI="meterCubed"
   abbreviation="l"
   multiplierToSI="0.001">
  <stm:description>Nearly 1 dm**3 This is not quite exact</stm:description>
</stm:unit>
<!-- ... -->
<stm:unit id="fahr" name="fahrenheit" parentSI="k"
   abbreviation="F"
  multiplierToSI="0.55555555555555555"
  constantToSI="-17.777777777777777777">
  <stm:description>An obsolescent unit of temperature still used in popular
  meteorology</stm:description>
</stm:unit>
</stm:unitList>