Sometimes disabled items may still appear in some modded menus, such as this one

This may confuse players when they can't find the item shown in the menu, so the option to add a simply [DISABLED] or [UNOBTAINABLE] item somewhere in the name would be nice.

How I'd do it is change the name to [DISABLED ITEM], change the model to the barrier inventory model, and probably put the item description as:
"This item is disabled. It will not be"
"obtainable in-game via any means"

The line break is intentional so the item tooltip box doesn't get too long. An ability to turn this on would be nice. Possibly with the "barrier inventory model" idea being a separate toggle, in case a pack maker wants the player to know what in the modded menu is disabled more easily.