<xsl:copy> element transfers a shallow copy (the node and any associated namespace node) of the current node to the output document. It does not copy any children or attributes of the current node.
<xsl:copy use-attribute-sets=LIST-OF-NAMES> TEMPLATE </xsl:copy>
Lists attribute sets that should be applied to the output node, if it is an element. Names of the sets should be separated with whitespace characters.
Instruction, appears within a template.
XSLT, section 7.5.