An agreement typically involves the exchange of goods, services, money, or promises of any of those. In the event of breach of contract, the law awards the injured party access to legal remedies such as damages and cancellation. In cases where standard contract is not used, written evidence of engagements is essential. A letter or note should specify the date, time and place of the engagement, the fee, and that the engagement is subject to a set of terms and conditions. Such a letter or note should be signed by someone fully authorised to do so.