Error in ITS rules in its.sch

Are we sure the ITS rules in its.sch (especially the locNoteRule ones) are correct?
I’m getting syntax errors like “A location step was expected following the '/' or '//' token.” When trying to process them.

I’m certainly no XPath expert, but the “//::” parts look odd.

For example a rule like:

//xlf:file//::xlf:source[ancestor::xlf:file[not(@appliesTo)]/xlf:notes/xlf:note[@priority=1]] | //xlf:file[not(@appliesTo)]//::xlf:target[ancestor::xlf:file[not(@appliesTo)]/xlf:notes/xlf:note[@priority=1]]