Sell is a command that is used in rooms with a shopkeeper mob. It exchanges one of your items for its equivalent cash value.
Additionally, sell can be used at inns to sell stored items for rent credit.
In Game Description[]
Syntax: sell <item> This attempts to persuade a shopkeeper to buy one of your items in order to gain a little bit of cash. Shopkeepers are notorious for trying to shortchange and swindle people, though, and may not even be interested in a particular item you wish to sell. Example: > sell longsword