diff --git a/_site/kinds/5400/index.html b/_site/kinds/5400/index.html
index d210878..1add082 100644
--- a/_site/kinds/5400/index.html
+++ b/_site/kinds/5400/index.html
@@ -92,6 +92,15 @@ <h1 id="params">Params</h1>
 
 <ul>
   <li><code class="language-plaintext highlighter-rouge">relay</code>: a relay url to include in the count (required, client MAY provide more than one relay)</li>
+  <li><code class="language-plaintext highlighter-rouge">group</code>: an event field or tag name to group results by, resulting in a potentially nested dictionary of results (optional, client MAY provide more than one group). Supported groups include:
+    <ul>
+      <li><code class="language-plaintext highlighter-rouge">content</code> - an event’s <code class="language-plaintext highlighter-rouge">content</code> field</li>
+      <li><code class="language-plaintext highlighter-rouge">pubkey</code> - an event’s <code class="language-plaintext highlighter-rouge">pubkey</code> field</li>
+      <li><code class="language-plaintext highlighter-rouge">reply</code> - an event’s <code class="language-plaintext highlighter-rouge">reply</code> e-tag</li>
+      <li><code class="language-plaintext highlighter-rouge">root</code> - an event’s <code class="language-plaintext highlighter-rouge">root</code> e-tag</li>
+      <li>Any other value will be assumed to be a tag name. The first matching tag’s value will be used.</li>
+    </ul>
+  </li>
 </ul>
 
 <h1 id="how-clients-can-use-this">How clients can use this</h1>
@@ -119,6 +128,23 @@ <h4 id="response">Response</h4>
     </span><span class="nl">"kind"</span><span class="p">:</span><span class="w"> </span><span class="mi">6400</span><span class="p">,</span><span class="w">
     </span><span class="nl">"content"</span><span class="p">:</span><span class="w"> </span><span class="s2">"129469"</span><span class="w">
 </span><span class="p">}</span><span class="w">
+</span></code></pre></div></div>
+
+<h4 id="request-1">Request</h4>
+<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
+    </span><span class="nl">"content"</span><span class="p">:</span><span class="w"> </span><span class="s2">"[{</span><span class="se">\"</span><span class="s2">#kinds</span><span class="se">\"</span><span class="s2">:[7], </span><span class="se">\"</span><span class="s2">#e</span><span class="se">\"</span><span class="s2">:[</span><span class="se">\"</span><span class="s2">7b0d90f1973da1cea186c85fbd09b3e4e455ce4d438b60a3d1f9aabc1681418f</span><span class="se">\"</span><span class="s2">}]"</span><span class="p">,</span><span class="w">
+    </span><span class="nl">"kind"</span><span class="p">:</span><span class="w"> </span><span class="mi">5400</span><span class="p">,</span><span class="w">
+    </span><span class="nl">"tags"</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="w">
+      </span><span class="p">[</span><span class="s2">"param"</span><span class="p">,</span><span class="w"> </span><span class="s2">"group"</span><span class="p">,</span><span class="w"> </span><span class="s2">"content"</span><span class="p">]</span><span class="w">
+    </span><span class="p">]</span><span class="w">
+</span><span class="p">}</span><span class="w">
+</span></code></pre></div></div>
+
+<h4 id="response-1">Response</h4>
+<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
+    </span><span class="nl">"kind"</span><span class="p">:</span><span class="w"> </span><span class="mi">6400</span><span class="p">,</span><span class="w">
+    </span><span class="nl">"content"</span><span class="p">:</span><span class="w"> </span><span class="s2">"{</span><span class="se">\"</span><span class="s2">🤙</span><span class="se">\"</span><span class="s2">:224,</span><span class="se">\"</span><span class="s2">+</span><span class="se">\"</span><span class="s2">:31,</span><span class="se">\"</span><span class="s2">🧡</span><span class="se">\"</span><span class="s2">:2,</span><span class="se">\"</span><span class="s2">❤️</span><span class="se">\"</span><span class="s2">:7,</span><span class="se">\"</span><span class="s2">🤣</span><span class="se">\"</span><span class="s2">:3,</span><span class="se">\"</span><span class="s2">⚡</span><span class="se">\"</span><span class="s2">:2,</span><span class="se">\"</span><span class="s2">💜</span><span class="se">\"</span><span class="s2">:7,</span><span class="se">\"</span><span class="s2">:thinking face:</span><span class="se">\"</span><span class="s2">:1,</span><span class="se">\"</span><span class="s2">🦶</span><span class="se">\"</span><span class="s2">:1,</span><span class="se">\"</span><span class="s2">🍺</span><span class="se">\"</span><span class="s2">:1,</span><span class="se">\"</span><span class="s2">🍆</span><span class="se">\"</span><span class="s2">:2,</span><span class="se">\"</span><span class="s2">🤙🏼</span><span class="se">\"</span><span class="s2">:3,</span><span class="se">\"</span><span class="s2">🔥</span><span class="se">\"</span><span class="s2">:2,</span><span class="se">\"</span><span class="s2">🏇</span><span class="se">\"</span><span class="s2">:1,</span><span class="se">\"</span><span class="s2">💚</span><span class="se">\"</span><span class="s2">:1}"</span><span class="w">
+</span><span class="p">}</span><span class="w">
 </span></code></pre></div></div>
 
 						</div><!-- /.content -->
diff --git a/kinds/5400.md b/kinds/5400.md
index 3432de9..1ccacb4 100644
--- a/kinds/5400.md
+++ b/kinds/5400.md
@@ -15,6 +15,12 @@ The input MUST be a JSON-encoded list of filters as specified in NIP 01.
 # Params
 
 * `relay`: a relay url to include in the count (required, client MAY provide more than one relay)
+* `group`: an event field or tag name to group results by, resulting in a potentially nested dictionary of results (optional, client MAY provide more than one group). Supported groups include:
+  * `content` - an event's `content` field
+  * `pubkey` - an event's `pubkey` field
+  * `reply` - an event's `reply` e-tag
+  * `root` - an event's `root` e-tag
+  * Any other value will be assumed to be a tag name. The first matching tag's value will be used.
 
 # How clients can use this
 
@@ -42,3 +48,22 @@ Clients may want to avoid downloading large datasets from many relays simply in
     "content": "129469"
 }
 ```
+
+#### Request
+```json
+{
+    "content": "[{\"#kinds\":[7], \"#e\":[\"7b0d90f1973da1cea186c85fbd09b3e4e455ce4d438b60a3d1f9aabc1681418f\"}]",
+    "kind": 5400,
+    "tags": [
+      ["param", "group", "content"]
+    ]
+}
+```
+
+#### Response
+```json
+{
+    "kind": 6400,
+    "content": "{\"🤙\":224,\"+\":31,\"🧡\":2,\"❤️\":7,\"🤣\":3,\"⚡\":2,\"💜\":7,\":thinking face:\":1,\"🦶\":1,\"🍺\":1,\"🍆\":2,\"🤙🏼\":3,\"🔥\":2,\"🏇\":1,\"💚\":1}"
+}
+```