bz64905 Specify that SSIStartTag/SSIEndTag may not contain whitespace.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1932483 13f79535-47bb-0310-9956-ffa450edef68

Author: rbowen

docs/manual/mod/mod_include.xml

@@ -848,6 +848,10 @@ Options +Includes
 SSIEndTag "%>"
     </highlight>
 
+    <note type="warning">
+    Value may not include any whitespace.
+    </note>
+
 </usage>
 <seealso><directive module="mod_include">SSIStartTag</directive></seealso>
 </directivesynopsis>
@@ -919,6 +923,10 @@ SSIStartTag "&lt;%"
 SSIEndTag   "%&gt;"
     </highlight>
 
+    <note type="warning">
+    Value may not include any whitespace.
+    </note>
+
     <p>The example given above, which also specifies a matching
     <directive module="mod_include">SSIEndTag</directive>, will
     allow you to use SSI directives as shown in the example