| Microsoft XML Core Services (MSXML) 5.0 for Microsoft Office - XSLT Developer's Guide |  |
Comments in XSLT
Comments in XSLT work the same as comments in XML. You can comment out a block of XSLT elements. You cannot comment out text inside a start tag, such as <xsl:value-of <!-- mycomment--> select="book">. This causes an error.
See Also
Generating Comments, Processing Instructions, and Elements | xsl:comment Element | Comments (XML Developer's Guide)