XLIFF 2.0 Comments - Missing description

Comments on XLIFF Version 2.0 Committee Specification Draft 01
http://docs.oasis-open.org/xliff/xliff-core/v2.0/csprd01/xliff-core-v2.0-csprd01.pdf

"The <file> element must not have a <skeleton> child, if and only if the optional skeleton attribute is used."

There is no attribute skeleton defined in the description of <file>.

-ys