svn commit: r1770154 - /httpd/httpd/branches/2.4.x/docs/manual/mod/mod_headers.html.en

[el...@apache.org]

Author: elukey
Date: Thu Nov 17 10:52:21 2016
New Revision: 1770154

URL: http://svn.apache.org/viewvc?rev=1770154&view=rev
Log:
documentation rebuild

Modified:
    httpd/httpd/branches/2.4.x/docs/manual/mod/mod_headers.html.en

Modified: httpd/httpd/branches/2.4.x/docs/manual/mod/mod_headers.html.en
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.4.x/docs/manual/mod/mod_headers.html.en?rev=1770154&r1=1770153&r2=1770154&view=diff
==============================================================================
--- httpd/httpd/branches/2.4.x/docs/manual/mod/mod_headers.html.en (original)
+++ httpd/httpd/branches/2.4.x/docs/manual/mod/mod_headers.html.en Thu Nov 17 10:52:21 2016
@@ -309,8 +309,16 @@ available in 2.4.10 and later</td></tr>
 
     <dt><code>setifempty</code></dt>
     <dd>The request header is set, but only if there is no previous header
-    with this name.<br />
-    Available in 2.4.7 and later.</dd>
+    with this name.
+    <div class="note">
+    The Content-Type header is a special use case since there might be
+    the chance that its value have been determined but the header is not part
+    of the response when <code>setifempty</code> is evaluated.
+    It is safer to use <code>set</code> for this use case like in the
+    following example:
+    <pre class="prettyprint lang-config">Header set Content-Type "text/plain" "expr=-z %{CONTENT_TYPE}"</pre>
+
+    </div></dd>
 
     <dt><code>unset</code></dt>
     <dd>The response header of this name is removed, if it exists.