It should not be possible to use a result tree
fragment in contexts that require a node-set when the
effective version of the stylesheet is 1.0. But a
simple call of <xsl:apply-template select="$rtf"/>
succeeds, because the check is not being made in this
situation (it is made only when a path expression or
filter expression is used).
Applies to 6.5.2 and all earlier releases. Not
applicable to 7.x, which does not enforce any
restrictions on RTF-to-nodeset conversion, regardless
of the version number.