An option (khiyar) that comes into effect if the buyer finds out that a desired feature or specification of the object of sale is actually missing or non-existing. The buyer has the option either to accept the sale as is (without any partial refund of the price) or to reject it if the missing feature is one of a particular importance to him. This option is usually used in cases where the object of sale is not available at the time of contract.

For example, a person may buy a vehicle based on the description that it has traveled a specific mileage or is the model of a given year just to discover later that this is not true. As such, the buyer has the option to retain the object without any refund or to call off the sale altogether. Conventionally, since the buyer would not have accepted the underlying object without a specific feature, then its absence is tantamount to a defect (aib/ ayb) in the object.

Khiyar al-wasf is an Arabic term (خيار الوصف) that translates as missing feature option or feature-related option.