diff --git a/Upgrading-Omeka-core.md b/Upgrading-Omeka-core.md
index dcdcc25..aec1152 100644
--- a/Upgrading-Omeka-core.md
+++ b/Upgrading-Omeka-core.md
@@ -30,7 +30,8 @@ Then edit the new file, adding these lines `-->>`
     <?php endforeach; ?>
 ```
 
-**HTML**:  Users can paste text into the Omeka HTML block. This is undesirable because html style and classes are included in the html. We de not want unexpected formats. Edit the core to filter html tags and attributes.
+## HTML filter
+Users can paste text into the Omeka HTML block. This is undesirable because html style and classes are included in the html. We de not want unexpected formats. Edit the core to filter html tags and attributes.
 
 `./application/src/Site/BlockLayout/Html.php`