Feature summary:
Add a duplicate feature to references in VisualEditor.

(new action is drawn in red-orange; doesn't mean that color should actually be red-orange though :))

Proposed workflow:

1. Edit an article using VisualEditor
2. Click on any reference
3. Click on a new "Duplicate" action
4. If you selected <ref name="abc"/> it would create a new ref with some new name: <ref name=":1">...content of name=abc...</ref>

Use case(s):

• Use an existing reference as a "template" for creating a new one (e.g. when a user want's to re-use certain formatting styles)
• Use an existing reference to create a similar (but not identical) reference, e.g. different edition or page number

Currently to duplicate a reference you have to:

1. Open another browser tab with a 2nd article.
2. VE-Edit the 2nd article.
3. Go back to original, 1st article.
4. Copy from 1st to 2nd.
5. Copy back from 2nd to 1st.

Current procedure is very hard to discover and even then it takes some setup to execute...

Benefits:

• Changing only one instance of a re-used reference in VisualEditor is not possible currently (except when using the workaround described above)
• Duplicating references in VisualEditor could be much easier (and much, much more discoverable)
• Implementing a duplication feature will make referencing workflows easier for VisualEditor-users

Other information:
Sub-referencing implemented a feature to address this need: T406461: VE: Enable user to make a choice to edit all sub-ref or only one. (and T406454)