Add compatibility note

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1684311 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/docs/manual/mod/mod_logio.xml b/docs/manual/mod/mod_logio.xml
index 65d66a2d923880b89e5008618fc3090e617372bd..847b5d3176d7bc284a8850e8f6e7157a53138481 100644 (file)
--- a/docs/manual/mod/mod_logio.xml
+++ b/docs/manual/mod/mod_logio.xml
@@ -76,8 +76,8 @@
     <tr><td><code>%^FB</code></td>
         <td>Delay in microseconds between when the request arrived and the
         first byte of the response headers are written.  Only available if
-        <directive>LogIOTrackTTFB</directive> is set to ON.
-        </td></tr>
+        <directive>LogIOTrackTTFB</directive> is set to ON.<br />
+        Available in Apache 2.4.13 and later</td></tr>
     </table>
 
     <p>Usually, the functionality is used like this:</p>