[object / reviews] it makes sense to combine reviews for all products with the same Group ID. In this case, the review is on the hardcover version of the book, and it makes sense to show it on the paperback as well. #4752
[search / group ID] if the objects have the same Group ID, then only one option should be shown in the search results (preferably the one that satisfies the query as much as possible) #4511
[product / group id] two products have a common Group ID, but one of the products shows the other, while the other does not #4997
[objects / Group ID] make Group IDs clickable so that you can quickly see all objects with the same ID (display - similar to Departments inside objects) #5018