diff --git a/HISTORY.md b/HISTORY.md
index 405f6a1b..4b13ff48 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -16,6 +16,7 @@ http://visjs.org
### Timeline
+- Implemented support for attaching HTML attributes to items.
- Fixed moment.js url in localization example.
- Fixed `className` of groups not being updated when changed.
- Fixed the `id` field of a new item not correctly generated.
diff --git a/examples/timeline/23_data_attributes.html b/examples/timeline/23_data_attributes.html
index 4ccf0857..477f1a80 100644
--- a/examples/timeline/23_data_attributes.html
+++ b/examples/timeline/23_data_attributes.html
@@ -13,6 +13,10 @@
+
+ In this example all items get an HTML attribute attached: each item gets an attribute data-id, and items 1 and 6 have an additional attribute data-tooltip.
+