> For date values, whitespace can't be used this way, because Roundup's
> date specs can contain whitespace.  (...) For both cases (and for
> floats as well, of course), there are two possibilities they have in
> common:
> - the 'or' operator
> - inside curly brackets, the semicolon divides values, but changes
>   nothing about the nature of the enumeration-implying curly bracket.

Correction: Of course, we'll use (consistently) commas or 'or' for date
enumerations.  As mentioned elsewhere, enumerations of float values
don't make much sense;  thus I suggest to drop them.