(1) The auction is permitted only after the obligee has been warned about it; the warning may be omitted if the thing is vulnerable to spoilage and postponement of the auction entails danger.
(2) The obligor is to notify the obligee of the auction without undue delay; in the event of failure to do so, the obligor will be liable in damages.
(3) The warning and the notice may be omitted if they are inadvisable.