diff --git a/web_timeline/static/description/index.html b/web_timeline/static/description/index.html
index 338104146..f2714f975 100644
--- a/web_timeline/static/description/index.html
+++ b/web_timeline/static/description/index.html
@@ -435,6 +435,10 @@ the possible attributes for the tag:</p>
 <td>No</td>
 <td>When set to true, it allows to edit the events in a popup. If not (default value), the record is edited changing to form view.</td>
 </tr>
+<tr><td>stack</td>
+<td>No</td>
+<td>When set to false, items will not be stacked on top of each other such that they do overlap.</td>
+</tr>
 <tr><td>colors</td>
 <td>No</td>
 <td>Allows to set certain specific colors if the expressed condition (JS syntax) is met.</td>