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

[Jonathan Gregory]

Dear Martin

It would be more restrictive than your list, but it would be consistent, I
suppose, to use the same list permitted for netCDF variable/dim/attr names viz

alphanumeric characters, underscore '_', period '.', plus '+', hyphen '-', or
at sign '@'

Since these are ASCII char arrays, accented etc chars should be excluded
anyway by that, shouldn't they?

Best wishes

Jonathan