In IE, if you create an unordered list with the style "Custom" and you select an item of the list, a box of anchors appears around it (see screenshot) making it possible to resize it. It also makes it hard to edit the text of the list item, because most of the time the cursor does not appear inside the text when you clic on it.
The resizing is also lost on save.

This only happens in IE10 or IE11 and with this specific list style.