From: Bruce D'Arcus
> What's the basis on which level two and three features are distributed?
"are" distributed or "would be" distrubuted? At this point the distribution is just a suggestion, and comments are solicited.
Level 0 is straightforward: anything reatained in the spec that conforms to ISO 8601. (And I propose to eliminate the distinction of whether or not it is part of W3CDTF.) And so those features retained that are not part of ISO 8601 would be distributed over levels 2 and 3, and the question is on what basis. I see three factors: 1. difficulty of implementation; 2. need; 3. separability.
By "separability" I mean that I think we would want the BNF to be three (somewhat) distinct sections (perhaps all referencing a common part) corresponding to the three levels. Placing a feature in level 2 vs. level 3 (or vice versa) might make it easier (or more difficult) to achieve the desired separability.
I plan to begin looking at the BNF in terms of the above, but I would appreciate input from implementers and users about which features should be level 2 and which should be level 3.
> On Thu, Jun 2, 2011 at 2:50 PM, Ray Denenberg, Library of Congress
> <[log in to unmask]> wrote:
> > Saašha, I do think the three-level suggestion has merit and is worth
> considering further.
> > The spec could be represented as:
> > Level 0: a profile of 8601
> > Level 1: first-level extensions
> > Level 2: second level extensions
> > And to claim conformance, you must at least support level 1 (support
> for level 2 includes support for level 1).
> > Level 0 would be the 100 and 200 features.
> > For level 1, I suggest:
> > - uncertain/approximate excluding internal.
> > - intervals, excluding those with uncertain/approximate and temporal
> expressions, but including open and unknown.
> > - masking with "u"
> > Level 2:
> > - Lists (one of a set, all of a set)
> > - internal uncertain/approximate
> > - temporal expressions
> > - calendar
> > - long year
> > - season
> > - masking with "x"
> > Please comment. I will hold off on further BNF changes pending some
> agreement on this.
> > --Ray