diff --git a/install/fpm/configuration.xml b/install/fpm/configuration.xml
index a9c144c54aeb..87ade34cb21a 100644
--- a/install/fpm/configuration.xml
+++ b/install/fpm/configuration.xml
@@ -803,117 +803,157 @@
            </row>
           </thead>
           <tbody>
+           <row>
+            <entry>
+             <literal>%%</literal>
+            </entry>
+            <entry>The <literal>%</literal> character</entry>
+           </row>
            <row>
             <entry>
              <literal>%C</literal>
             </entry>
-            <entry>%CPU</entry>
+            <entry>
+             %CPU used by the request. It can accept the following format:
+             <literal>%{user}C</literal> for user CPU only,
+             <literal>%{system}C</literal> for system CPU only,
+             <literal>%{total}C</literal> for user + system CPU (default)
+            </entry>
            </row>
            <row>
             <entry>
              <literal>%d</literal>
             </entry>
             <entry>
-             duration. accepts following formats for precision:
+             Time taken to serve the request. It can accept the following formats for precision:
              <literal>%{seconds}d</literal> (default), <literal>%{milliseconds}d</literal>,
-             <literal>%{microseconds}d</literal>.
+             <literal>%{microseconds}d</literal>
             </entry>
            </row>
            <row>
             <entry>
-             <literal>%e</literal>
+             <literal>%{<replaceable>name</replaceable>}e</literal>
+            </entry>
+            <entry>
+             A variable from the server environment (same as <varname>$_ENV</varname> or <varname>$_SERVER</varname>).
+             A variable name must be specified within curly brackets.
+             For example: server specifics like: <literal>%{REQUEST_METHOD}e</literal> or
+             <literal>%{SERVER_PROTOCOL}e</literal>, HTTP headers like:
+             <literal>%{HTTP_HOST}e</literal> or <literal>%{HTTP_USER_AGENT}e</literal>
             </entry>
-            <entry>fastcgi env</entry>
            </row>
            <row>
             <entry>
              <literal>%f</literal>
             </entry>
-            <entry>script</entry>
+            <entry>Script filename</entry>
            </row>
            <row>
             <entry>
              <literal>%l</literal>
             </entry>
-            <entry>content length</entry>
+            <entry>
+             <literal>Content-Length</literal> of the request (for HTTP POST request only)
+            </entry>
            </row>
            <row>
             <entry>
              <literal>%m</literal>
             </entry>
-            <entry>method</entry>
+            <entry>Request HTTP method</entry>
            </row>
            <row>
             <entry>
              <literal>%M</literal>
             </entry>
-            <entry>memory</entry>
+            <entry>
+             Peak of memory allocated by PHP. It can accept the following format:
+             <literal>%{bytes}M</literal> (default), <literal>%{kilobytes}M</literal>
+             <literal>%{kilo}M</literal>, <literal>%{megabytes}M</literal>,
+             <literal>%{mega}M</literal>
+            </entry>
            </row>
            <row>
             <entry>
              <literal>%n</literal>
             </entry>
-            <entry>pool name</entry>
+            <entry>Pool name</entry>
            </row>
            <row>
             <entry>
-             <literal>%o</literal>
+             <literal>%{<replaceable>name</replaceable>}o</literal>
+            </entry>
+            <entry>
+             Output header. The header name must be specified within curly brackets.
+             For example: <literal>%{Content-Type}o</literal>,
+             <literal>%{X-Powered-By}o</literal>, <literal>%{Transfer-Encoding}o</literal>
             </entry>
-            <entry>header output</entry>
            </row>
            <row>
             <entry>
              <literal>%p</literal>
             </entry>
-            <entry>PID</entry>
+            <entry>PID of the child that serviced the request</entry>
+           </row>
+           <row>
+            <entry>
+             <literal>%P</literal>
+            </entry>
+            <entry>PID of the parent of the child that serviced the request</entry>
            </row>
            <row>
             <entry>
              <literal>%q</literal>
             </entry>
-            <entry>query string</entry>
+            <entry>The query string</entry>
            </row>
            <row>
             <entry>
              <literal>%Q</literal>
             </entry>
-            <entry>the glue between %q and %r</entry>
+            <entry>
+             The <literal>'?'</literal> character, or glue between <literal>%q</literal> and <literal>%r</literal>,
+             if query string exists
+            </entry>
            </row>
            <row>
             <entry>
              <literal>%r</literal>
             </entry>
-            <entry>request URI</entry>
+            <entry>
+             The request URI (without the query string,
+             see <literal>%q</literal> and <literal>%Q</literal>)
+            </entry>
            </row>
            <row>
             <entry>
              <literal>%R</literal>
             </entry>
-            <entry>remote IP address</entry>
+            <entry>Remote IP address</entry>
            </row>
            <row>
             <entry>
              <literal>%s</literal>
             </entry>
-            <entry>status</entry>
+            <entry>Status (response code)</entry>
            </row>
            <row>
             <entry>
-             <literal>%T</literal>
+             <literal>%t</literal>
             </entry>
-            <entry>time</entry>
+            <entry>Server time the request was received</entry>
            </row>
            <row>
             <entry>
-             <literal>%t</literal>
+             <literal>%T</literal>
             </entry>
-            <entry>time</entry>
+            <entry>Time the log has been written (the request has finished)</entry>
            </row>
            <row>
             <entry>
              <literal>%u</literal>
             </entry>
-            <entry>remote user</entry>
+            <entry>Remote user</entry>
            </row>
           </tbody>
          </tgroup>