This is pretty rare but some games might use depot ids to see if dlcs are installed. You can provide a list of installed depots to the game with a steam_settings\depots.txt file.
See the steam_settings.EXAMPLE folder for an example.
Subscribed Groups:
Some games like payday 2 check which groups you are subscribed in and unlock things based on that. You can provide a list of subscribed groups to the game with a steam_settings\subscribed_groups.txt file.
See steam_settings.EXAMPLE\subscribed_groups.EXAMPLE.txt for an example for payday 2.
App paths:
Some rare games might need to be provided one or more paths to app ids. For example the path to where a dlc is installed. This sets the paths returned by the Steam_Apps::GetAppInstallDir function.
See steam_settings.EXAMPLE\app_paths.EXAMPLE.txt for an example.