From Red Hat Apache Guru Mark Cox, via Drew Meeks at Red Hat:
AddingHeader add MSSmartTagsPreventParsing "TRUE"
to httpd.conf should add the response header to every page served.
Mark and Drew haven’t tested this, but I pass it along. You can test the efficacy of this approach at http://220.127.116.11/, which returns bothMSSmartTagsPreventParsing: TRUE X-Meta-MSSmartTagsPreventParsing: TRUE
as response headers, the latter since X-Meta-Foo in the response headers is interpreted by some browsers as equivalent to a <META name=”Foo”> tag. http://18.104.22.168/ returns the same content without the above headers.
Requires that mod_headers is installed on your copy of Apache: See http://httpd.apache.org/docs/mod/mod_headers.html. You can alter the scope of this by placing the “Header” directive inside a VirtualHost, Directory, Location, or Files directive.
I grabbed the whole thing incase the refered site disapears in the future.