Allow DLCs, Expansions, Packs/Addons, Updates, Seasons, and Mods to be applied to multiple games
Some games share additional content such as DLC, Expansions, Packs/Addons, Updates, Seasons, and Mods with ports of their game or sequels. While this would be a limited specific use case it will allow content pages to be shared between titles and limiting duplicates.
A great example is Minecraft. The latest update for Minecraft, the 1.19 Wild Update appears twice on IGDB. Once for the original Minecraft: Java Edition and another for the port Minecraft: Bedrock Edition. These two pages contain the same content and there isn't much of a reason for it to be separate.
Java: https://www.igdb.com/games/minecraft-the-wild-update
Bedrock: https://www.igdb.com/games/minecraft-the-wild-update--1
Another great example while not yet listed on IGDB is cosmetic bundles/packs for Call of Duty: Vanguard and Call of Duty: Warzone. The Call of Duty: Vanguard - Elegant Threat Pro Pack as an example contains cosmetics that can be used both in Vanguard and Warzone. If and when this content is added to IGDB, it would have to be added twice one for each title.
https://us.shop.battle.net/en-us/product/call-of-duty-vanguard-s5-elegant-threat?p=873257
I'm sure this will need some discussion and changes to the contribution guidelines specifying how this can be used. I'm happy to answer questions about my idea. Thanks for considering my suggestion!