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Units in the VO
Version 1.0

IVOA Recommendation 23 May 2014

Interest/Working Group:
Markus Demleitner, Sebastien Derriere, Norman Gray, Mireille Louys, Francois Ochsenbein
Sebastien Derriere, Norman Gray


This document describes a recommended syntax for writing the string representation of unit labels ("VOUnits"). In addition, it describes a set of recognised and deprecated units, which is as far as possible consistent with other relevant standards (BIPM, ISO/IEC and the IAU). The intention is that units written to conform to this specification will likely also be parsable by other well-known parsers. To this end, we include machine-readable grammars for other units syntaxes.

Status of this document

This document has been produced by the Semantics Working Group.
It has been reviewed by IVOA Members and other interested parties, and has been endorsed by the IVOA Executive Committee as an IVOA Recommendation. It is a stable document and may be used as reference material or cited as a normative reference from another document. IVOA's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability inside the Astronomical Community.

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