Section 9.9 concerning the scope of variables contains no mention of packages. A reader who reads this section in isolation, without first becoming familiar with the sections of the spec concerning packages, may find the current wording misleading.

Specifically, the paragraph that reads:

A global variable binding element is visible everywhere in the stylesheet (including other stylesheet modules) except within the xsl:variable or xsl:param element itself and any region where it is shadowed by another variable binding.

would be clearer if it read:

A global variable binding element is visible everywhere in the containing package (including other stylesheet modules) except within the xsl:variable or xsl:param element itself and any region where it is shadowed by another variable binding. (For rules regarding the visibility of the variable in other packages, see 3.5.3.1.)