When adding a new title to your Title Manager, you will need to assign an ISBN13 to it. If the ISBN13 you want to use is already assigned to another title, you will see an error message on your screen. It will read: “This ISBN13 is already in use,” as below.
To see which title is already connected to the ISBN13 you've written, copy-paste it into the search box at the main Books screen. If the search doesn't have any results, the title might be in archived or hidden items. You can check that by clicking on the Show Archived button:
And then copy-paste the ISBN13 into the search box.
If it is still not there, click on the Show Hidden Button:
To archive a text: tick the box that reads "Archived/Deleted" in front of the title and then click the Remove Selected button. If you are within the title's data in Title manager, you can also archive the text by clicking on ISBN tab and ticking the Archived/Deleted box:
To activate the title again just un-tick the box.
To hide a title: click on the symbol in the green square below:
After this, a Title Management box will come up on the screen. If the item is hidden, the box will be empty:
To un-hide the title just tick the Title Management box.