I love this addon and it broke a few patches ago. I decided to clean it up to remove most of the errors. While I was at it I added a feature to filter out items from any guild bank (a checkbox above the search button).
My goal with this update was to make Possessions usable again. I'm not an addon expert so if someone wants to take over maintenance and clean up every feature (specifically the slots filter), feel free to post in the comments forum or provide a link and I'll add the link to this description. Here is the old description for anyone new to Possessions:
Possessions is an AddOn to keep track of all your... possessions.
It will keep track of the items on all your alts (per server), including worn items, items in your inventory, items in your bank and even items in your mailbox (that you've seen).
In the Possessions window you can then filter the list to show items from a certain player or a certain location.
The items are grouped together and the tooltip will show you how many you have of the item at each location.
So, if you want to see if you have any silk cloth anywhere you can just do '/poss silk cloth', and Possessions will show, in its window, all items matching 'silk cloth'. Mouseover that, and you'll see, for example, that you have 10 silk cloth in your bank, 50 silk cloth in your alt's inventory, and 5 silk cloth in your mailbox.
Additionally, Possessions will keep track of items you mail to known alts (so, if you mail an additional 5 silk to your alt, Possessions will know an additional 5 silk is in your alt's inbox, without relogging).