Causes an XML processing instruction to be output.
Permitted parent elements: any XSLT element whose content model is sequence-constructor; any literal result element
The name of the PI. This attribute is interpreted as an attribute value template, so it may contain string expressions within curly braces.
The data part of the PI may be given either
xsl:processing-instruction element can appear anywhere within an
xsl:template. Note that
special characters occurring within the PI text will not be escaped.