<tr><td><code>SSL_SERVER_A_SIG</code></td> <td>string</td> <td>Algorithm used for the signature of server's certificate</td></tr>
<tr><td><code>SSL_SERVER_A_KEY</code></td> <td>string</td> <td>Algorithm used for the public key of server's certificate</td></tr>
<tr><td><code>SSL_SERVER_CERT</code></td> <td>string</td> <td>PEM-encoded server certificate</td></tr>
-<tr><td colspan="3">[ where <em>x509</em> is a component of a X.509 DN:
- <code>C,ST,L,O,OU,CN,T,I,G,S,D,UID,Email</code> ]</td></tr>
</table>
+
+<p><em>x509</em> specifies a component of an X.509 DN; one of
+<code>C,ST,L,O,OU,CN,T,I,G,S,D,UID,Email</code>. In Apache 2.1 and
+later, <em>x509</em> may also include a numeric <code>_n</code>
+suffix. If the DN in question contains multiple attributes of the
+same name, this suffix is used as an index to select a particular
+attribute. For example, where the server certificate subject DN
+included two OU fields, <code>SSL_SERVER_S_DN_OU_0</code> and
+<code>SSL_SERVER_S_DN_OU_1</code> could be used to reference each.</p>
+
</section>
<section id="logformats"><title>Custom Log Formats</title>