diff --git a/README.md b/README.md
index 83a15ba..262e657 100644
--- a/README.md
+++ b/README.md
@@ -179,7 +179,7 @@ Point(x=1, y=2)
 Iterator
 --------
 ```python
-<iter> = iter(<collection>)
+<iter> = iter(<collection>)                 # Calling `iter(<iter>)` returns unmodified iterator.
 <iter> = iter(<function>, to_exclusive)     # Sequence of return values until 'to_exclusive'.
 <el>   = next(<iter> [, default])           # Raises StopIteration or returns 'default' on end.
 ```
diff --git a/index.html b/index.html
index 8464b69..c736cc3 100644
--- a/index.html
+++ b/index.html
@@ -320,7 +320,7 @@ Point(x=<span class="hljs-number">1</span>, y=<span class="hljs-number">2</span>
 (<span class="hljs-string">'x'</span>, <span class="hljs-string">'y'</span>)
 </code></pre>
 <h2 id="iterator"><a href="#iterator" name="iterator">#</a>Iterator</h2>
-<pre><code class="python language-python hljs">&lt;iter&gt; = iter(&lt;collection&gt;)
+<pre><code class="python language-python hljs">&lt;iter&gt; = iter(&lt;collection&gt;)                 <span class="hljs-comment"># Calling `iter(&lt;iter&gt;)` returns unmodified iterator.</span>
 &lt;iter&gt; = iter(&lt;function&gt;, to_exclusive)     <span class="hljs-comment"># Sequence of return values until 'to_exclusive'.</span>
 &lt;el&gt;   = next(&lt;iter&gt; [, default])           <span class="hljs-comment"># Raises StopIteration or returns 'default' on end.</span>
 </code></pre>