We already have /sea all [Player_Name] and various options available therein. I think it would be excellent to have a search for inventory areas.
If you could not find an item, you could simply search your inventory for it.
/search bank "Boreas Cesti"
/search locker "Boreas Cesti"
/search storage "Boreas Cesti"
/search satchel "Boreas Cesti"
It should then tell you the location and how many are found. If part of an item was listed, it would show all of it.
/search bank Crystal
This would show the number of items found that match within the Mog Bank.
Also, I know it would be more complicated, but a way to search all of the storage areas would be nice too. Most people are not aware of "/sea inv" which searches for people with their invite flags up so the word inventory might not be the best to use, but some alternates are possible.
/sea items Cesti
This would show all storage areas for this weapon such as "Boreas Cesti" and the regular "Cesti" along with the total number of items found. This could be display exactly like the player list. There are so many places where items are stored, I think a search method like this would prove beneficial to all players.