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John, The entries are correct. "radian" has no definition, so the default definition of the dimensionless unit one is used. The steradian definition of a square radian also results in a dimensionless unit. You can add those elements if you wish; it won't make any difference to the UDUNITS package. > Looking at udunits2-derived.xml, I see the following > (https://github.com/graybealski/UDUNITS-2/blob/master/lib/udunits2-derived.xml): > > > <unit> > > <dimensionless/> > > <name><singular>radian</singular></name> > > <symbol>rad</symbol> > > </unit> > > <unit> > > <def>rad^2</def> > > <name><singular>steradian</singular></name> > > <symbol>sr</symbol> > > </unit> > > Both of these are dimensionless units in the real world. yet the first has a > <dimensionless/> tag and no <def> tag, while the second has a <def> tag but > no <dimensionless/> tag. > > Should both of them have both <def> and <dimensionless/> tags? > > John > > --------------- > John Graybeal > Marine Metadata Interoperability Project: http://marinemetadata.org Regards, Steve Emmerson Ticket Details =================== Ticket ID: ZJA-671914 Department: Support UDUNITS Priority: Normal Status: Closed