UnitsML is a project underway at the (US) National Institute of Standards and Technology (NIST) to develop a schema for encoding scientific units of measure in XML. UnitsML allows encoding of scientific units of measure and quantities into XML and will validate XML documents that use UnitsML. Initial development of this schema was done at NIST, but completion of the development process should include input from the international scientific and engineering community.
Towards this end, NIST is initiating an OASIS Technical Committee to address any needed changes in the schema and publish a final recommendation. (See: http://unitsml.nist.gov/)
As OntoML does not cover units and quantities to the extent that is required within ECLASS XML 1.0, an additional format named unitsML is included.
The XML Schema is to be found here: ECLASS XML
Figure 1: UnitsML – XML Schema