I'm saying the folder was created by Catalina becuase you restored from a non Catalina backup. I never once said it was transferred from Mojave. If you formatted the drive and installed Catalina without coming from a backup and set it up as a new mac you would not have that folder.
Again, you are not understanding. First, a folder entitled "Relocated items" was not, nor has
EVER been, on any of my Macs, no matter what OS I was using.
Secondly, I am the one that created that "Documents" folder a long, long time ago. EVERY time I have done a fresh, clean, "virgin" installation of a new Mac OS, I followed this procedure:
1. Made sure I had the latest installation file for the new OS, and that it was
not inside the Applications folder.
2. Insured that ALL the third party applications I use were compatible with the new Mac OS.
3. Ran Onyx and TechTool Pro on my "base" machine.
4. Did a SuperDuper! backup to an external SSD (connected via USB 3.1) of my "base" machine/ system (only has 1 partition).
5. Re-started my "base" Mac from that just-created SuperDuper! backup.
6. Launched Disk Utility
there and Erased and Formatted the internal SSD on the "base" Mac.
7. Launched the new Mac OS Installer file
there (ie, on the backup), and did a fresh, clean, virgin installation of that new Mac OS onto that internal SSD.
8. When the installation was done, was afforded the opportunity to migrate (ie, copy) files, folders, apps, settings, etc. from either another Mac or a backup. I chose the just-created SuperDuper! backup. That process went smoothly (as expected).
9. Restarted my "base" Mac, and except for a couple of "house cleaning" chores, I was there.
In ALL of that, the Documents folder on my "base" Mac was
ALWAYS transferred/moved/copied (whatever you want to call it) correctly.
In my "Catalina" case, I started at step 6 (on my "base" Mac, ie, my Mac Mini, with the External Samsung 860 EVO 500 gig SSD attached, via USB 3.1), and did what I already mentioned above. But Catalina
could not properly handle that Documents folder, and thus 1) created the "Relocated Items" folder, and 2) copied/moved/transferred (again whatever you want to call it) the Documents folder from my Mac Mini to the location Users/Shared/Recovered Items/Security/Documents.
The ORIGINAL location of that Documents folder was, again, at the same "level" as the Applications, System, Library, and Users folders. Catalina did not place it in the same location.
Once again, I ask you to point me to the Apple "document" that discusses this.