From: Bruce D'Arcus
> One way to slice the levels is how different feature diverge from the
> base. For example, a standard range of "2002-02/2002-03" is not
> supported by Level 0, but it's components are.
That's a disturbing observation as I suppose I didn't realize that 8601 does not support "2002-02/2002-03". Thus features 208-211, which are represented as being 8601 conformant, aren't.
ISO 8601 is a horribly frustrating document to try to make sense out. It makes no common sense to me why 8601 wouldn't want to support "2002-02/2002-03"; I can see that it doesn't, but only by the lack of an example to the contrary. (At least as far as I can tell - and given 8601's general lack of examples, deciphering it based on it’s examples is not a comforting process.)
But I digress. If "2002-02/2002-03" is not a valid 8601 string while both "2002-02" and "2002-03" are, then I agree that it does make sense to cast "2002-02/2002-03" into level 1 rather than level 2. On the other hand, that seems to be the only feature that would fit this criterion and all else would be cast into level 2, which would make level 1 rather slim.