Step 6 of 9 in Making a new edition
Sample data, read from content-sdk
Where a copy came from
Humanities (Regional) has a Timeline Teach Book of its own. Where did it come from?
Every copy keeps what it was copied from, so the tools can follow it back to the original.
Try it: select Timeline Teach Book in Humanities (Regional), and read what it's a copy of in the panel.
The regional edition's copy came from Humanities' Timeline Teach Book. They're two resources now, and the line is all that connects them.