This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
An issue is in order to clarify that the four [xsi:] attributes must be validated using the built-in declarations whenever they appear, and must be valid, and get PSVI-only properties. This will require an extra clause in Element Locally Valid (Complex Type), and possibly in Schema Information Set Contribution: Assessment Outcome (Attribute). For additional info and background, see: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2003JulSep/0073.html
On the call of 16 March, the Working Group approved a wording proposal which makes clear that attributes in the xsi namespace must indeed be validated and do indeed appear in the PSVI. Accordingly, I'm marking this as fixed.