VOUnit for solar density or metallicity?

[Tom Donaldson]

 Hello VOUnits enthusiasts,

I was doing some validation on the units in our TESS Input Catalog (TIC) SCS and TAP results and came across one I didn’t see how to fix.  We have apparently been using unit=”Sun” on two different types of columns, one meaning solar metallicity and one meaning solar density.  Although "Sun" is mentioned in the VOUnits standard, I couldn't understand what was meant, and "Sun" is not on the list of known units (Table 2).

It's a little tempting to extrapolate from the known units "solLum", "solMass" and "solRad" and come up with something like "solDen" or even "solFEH", but those are obviously not on the known list either.

Does anyone have thoughts on whether there are official ways to represent these units, or if not, unofficial but preferable alternatives?

Thanks,
Tom