Sorry, I thought that was clear.
I'm trying to clean up the identifiers in my libraries, to get them down to just the ones that work as links from 'Ids:' on the book details panel. For example, the identifier: goodreads:5470 shows as 'Goodreads' on the book details panel on the righthand side of Calibre under the cover image where it says:
Ids: Goodreads
If you click where it says Goodreads it opens this link in your browser:
https://www.goodreads.com/book/show/5470.1984
The sonybookid identifiers don't show up under Ids:, and the site is gone, so I'm just trying to ascertain whether they are of any use before I remove them. I would just run 'Download Metadata & Covers' but it invariably makes mistakes so I have to manually check every one, and I'd rather not.