The 'General' tab of the IDLE configuration menu allows a user to add entries to the Help menu that display a text when clicked.  A user might want more than one text available for a given 'topic', such as a doc and how-to for a package.  However, there is no need to have duplicate entries, as up to 30 chars are allowed.  "Package - doc" and "Package - how" would be clearer than "Package" and "Package".  Issue 27380 makes checking for unique entries easy as that is already done for user configuration file section names and the same base class is now used for help source names.

Currently, names are displayed in the order added.  I believe sorting would be better, especially when one adds more than 2 entries.  That should also be easy.

Existing duplicates would not be a problem for IDLE as the check would only apply when adding or editing an item.  Python's stable list.sort would keep existing duplicates in the same relative order.  I will *not* use the doc path to break ties.