You may lose modification if you close an edit page without saving.
Description and Documentation
A warning will happen when you close an edit page if it has changes.
In addition, a different warning will happen when a person tries to save a topic without changing if the topic was last edited by somebody else. This is for a user who "Edit" a page only to see raw text and click "Save" thinking it makes no changes.
-- Contributors: Hideyo Imazu - 2016-11-03
This was discussed and accepted by KampalaReleaseMeeting2016x11x03
-- Peter Thoeny - 2016-11-03