underspecification in fallback to lax processing

As recently pointed out in an exchange between Sandy Gao and
Henry Thompson on the IG list (under the subject heading
"Validation rules for children of skipped elements"), the
paragraph at the end of Schema-Validity Assessment (Element)
is slightly underspecified.  It says:

  If the item cannot be strictly assessed, because neither
  clause 1.1 nor clause 1.2 above are satisfied, [Definition:]
  an element information item's schema validity may be laxly
  assessed _if its context-determined declaration is not skip_
  by validating with respect to the ur-type definition as per
  Element Locally Valid (Type)

[emphasis added by HT]

The spec does not say whether validation with respect to the
ur-type definition is allowed if the item's context-determined
declaration IS skip, or not.

The spec also does not call out this and other
implementation-dependent behaviors; it should.

I believe both of these (failure to forbid fallback to the
urtype for skipped subtrees, and failure to list
implementation-dependent behaviors) should be fixed in XML
Schema 1.1, and request that 1.1 issues be opened on these
topics.

-CMSMcQ