This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
What is the content type of the following? <complexType> <sequence min=max=0> <element .../> According to the complexType complexContent mapping rules, because there IS a sequence with an element child, the effective content is not empty, but is the particle corresponding to the sequence. But according to section 3.8.2, min=max=0 corresponds to no component at all. Shouldn't 2.1.1 of the definition of effective content in the mapping rules (of 2nd edition) be changed to: 2.1.1 There is no <group> <all> <choice> or <sequence> among the [children], which either doesn't have a maxOccur attribute, or the actual value of such attribute is not 0. See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2003JanMar/0038.html
There does seem to be a discrepancy between the two locations. But instead of making 2.1.1 more complicated, I think it would be simpler to address the case where the outermost group has min=max=0 with a separate clause (a new 2.1.4, that is), so that the beginning of 2.1 reads: 2.1 If one of the following is true 2.1.1 There is no <group>, <all>, <choice> or <sequence> among the [children]; 2.1.2 There is an <all> or <sequence> among the [children] with no [children] of its own excluding <annotation>; 2.1.3 There is a <choice> among the [children] with no [children] of its own excluding <annotation> whose minOccurs [attribute] has the ·actual value· 0; 2.1.4 The only <group>, <all>, <choice> or <sequence> among the [children] has a maxOccurs [attribute] with an actual value of 0; , then the appropriate case among the following: ... (I entertained an alternative analysis, that this case was correctly excluded, so as to create an unsatisfiable particle, but min=0 is never unsatisfiable, and min=max=0 is satisfied by the empty sequence, no matter what the min and max are on. So the particle created in the status quo accepts the empty sequence, and only the empty sequence. We might as well make it use the keyword.)
At its telcon of today, the WG accepted the analysis and wording proposal in comment #1. The change will appear in the next version of the status quo document.