[CF-metadata] Dealing with large numbers of flag values in netcdf cf -- what are "words"

[Jonathan Gregory]

Dear Martin

I would think that since words are blank-separated, they ought to be allowed
to include any character except white space. The convention says "If multi-word
phrases are used to describe the flag values, then the words within a phrase
should be connected with underscores." To allow phrases including spaces, we'd
need a different convention, such allowing flag meanings to be an array of
strings i.e. a 2D character array. I don't think that's possible in netCDF-
classic for an attribute, so the attribute would have to point to a variable
instead. If it is possible in netCDF-4, we could make it a feature of
CF specific to netCDF-4. Up to now we have not used new features of netCDF-4 in
the CF convention. Either way, a change to the CF standard would be required.

Best wishes

Jonathan