diff --git a/index.html b/index.html
index 365e67c4..4daedeaa 100644
--- a/index.html
+++ b/index.html
@@ -1620,10 +1620,10 @@ <h3>Proxy</h3>
 
  <tr>
   <td><code>httpProxy</code>
-  <td>string
+  <td>string or JSON <a>Object</a>
   <td>Defines the proxy <a>host</a> for HTTP traffic when
    the <a><code>proxyType</code></a> is "<code>manual</code>".
-  <td>A <a>host and optional port</a> for
+  <td>A <a>proxy specifier</a> for
    scheme "<code>http</code>".
  </tr>
 
@@ -1637,19 +1637,19 @@ <h3>Proxy</h3>
 
  <tr>
   <td><code>sslProxy</code>
-  <td>string
+  <td>string or JSON <a>Object</a>
   <td>Defines the proxy <a>host</a> for encrypted TLS traffic
    when the <a><code>proxyType</code></a> is "<code>manual</code>".
-  <td>A <a>host and optional port</a> for
+  <td>A <a>proxy specifier</a> for
    scheme "<code>https</code>".
  </tr>
 
  <tr>
   <td><code>socksProxy</code>
-  <td>string
+  <td>string or JSON <a>Object</a>
   <td>Defines the proxy <a>host</a> for a <a>SOCKS proxy</a>
    when the <a><code>proxyType</code></a> is "<code>manual</code>".
-  <td>A <a>host and optional port</a> with an <a>undefined</a> scheme.
+  <td>A <a>proxy specifier</a> with an <a>undefined</a> scheme.
  </tr>
 
  <tr>
@@ -1662,6 +1662,48 @@ <h3>Proxy</h3>
 
 </table>
 
+<p>A <dfn>proxy specifier</dfn> for a <var>scheme</var> is either a
+  <a>host and optional port</a> for a <var>scheme</var>, or a JSON
+  <a>Object</a> with the following properties:
+
+  <table class=simple>
+    <thead>
+      <tr>
+      <th>Key
+      <th>Value Type
+      <th>Description
+      <th>Valid values
+    </tr>
+    </thead>
+
+    <tr>
+      <td><code>protocol</code>
+      <td>string
+      <td>The protocol used to communicate with the proxy.
+      <td>"<code>http</code>",
+      "<code>ssl</code>",
+      "<code>socks4</code>",
+      "<code>socks5</code>".
+    </tr>
+
+    <tr>
+      <td><code>host</code>
+      <td>string
+      <td>The host used to connect to the proxy.
+      <td>Any <a>host</a> with optional
+        <a data-lt="includes credentials">credentials</a>.
+    </tr>
+
+    <tr>
+      <td><code>port</code>
+      <td>number
+      <td>The port used to connect to the proxy.
+      <td>Any valid <a>port</a>. If <code>protocol</code> is
+        "<code>socks4</code>" or "<code>socks5</code>", this field must be
+        omitted.
+    </tr>
+  </table>
+
 <p>A <dfn>host and optional port</dfn> for a <var>scheme</var> is
   defined as being a valid <a>host</a>, optionally followed by a colon
   and a valid <a>port</a>. The <a>host</a> may
@@ -1721,9 +1763,9 @@ <h3>Proxy</h3>
   an <a>error</a> with <a>error code</a> <a>invalid argument</a>.
 
  <li><p>If <var>proxy</var> has an <a>own property</a> for
-  "<code>socksProxy</code>" and does not have an <a>own property</a>
-  for "<code>socksVersion</code>" return an <a>error</a> with <a>error
-  code</a> <a>invalid argument</a>.
+  "<code>socksProxy</code>" which is a string, and does not have an
+  <a>own property</a> for "<code>socksVersion</code>" return an
+  <a>error</a> with <a>error code</a> <a>invalid argument</a>.
 
  <li><p>Return <a>success</a> with data <var>proxy</var>.
 </ol>