XSLT version for order confirmations

Hi all,

Does someone know the XSLT version in use for order confirmations? I'm trying to itemize fees by fee type, and am attempting to use xsl:for-each-group, which is an improved XSLT 2.0 mechanism for grouping nodes. However, I'm getting this error when it attempts to send out the order confirmation:

'xsl:for-each-group' is not yet implemented

I may be getting that due to an error on my part, but I'll never get it to work if XSLT 2.0 is not fully supported.

Thanks,
David