An incorrect XSLT URI.

Failure to provide a version.

Duplicate match patterns.

Modes that are used but never defined

Modes that are defined but never used

Named templates that are used but never defined

Named templates that are defined but never used

Templates that use name= where match= was probably intended

xsl:call-template elements that contain anything other than xsl:with-param

Variable/parameter references that are not defined at the point of use.

fo: elements that aren't part of the XSL 1.0 PR.

fo: element properties that aren't part of the XSL 1.0 PR.