It'd be nice, for RP purposes, to be able to create a custom item-set (e.g. via ID) that would allow people to keep track of an amount of items they have in their inventory or equipped.
Things like the Scourgelord's Battlegear have a full item-set list like this:
It'd be nice to be able to make a custom name for them and then add the corresponding item IDs underneath or something like that. To avoid any troubles with adding random people's items to a set, you can also just restrict it to only allow items you made yourself to be added, maybe via a dropdown list or by checking an item ID.