A contract of guarantee is a legally binding agreement in which a person agrees to bear the responsibilities, obligations, and liabilities of another person in case of default. This agreement is often used in business transactions where a third party intervenes to ensure that the contractual obligations are fulfilled.

While the contract of guarantee is a comprehensive legal document that outlines the terms and conditions of the agreement, there are some exceptions to the requirement of writing in certain situations. Here are some exceptions that you need to be aware of:

1. Oral guarantee: In some cases, a contract of guarantee can be formed through an oral agreement without any written documentation. However, it is important to note that an oral guarantee may be difficult to prove in court, especially if there are no witnesses to the agreement.

2. Unilateral guarantee: A unilateral guarantee is an agreement in which only one person undertakes to bear the responsibility of another person without any written documentation. This type of guarantee is often used in family or social settings where there is a high level of trust between the parties involved.

3. Continuing guarantee: A continuing guarantee is a type of agreement in which the guarantor agrees to bear the responsibility of the debtor for a fixed period. This type of guarantee does not require any written documentation as it is considered to be an ongoing agreement between the parties.

4. Bank guarantee: In some cases, a bank can provide a guarantee on behalf of a debtor without any written documentation. This type of guarantee is often used in business transactions where the bank acts as a third party to ensure that the debtor fulfills its obligations.

5. Implied guarantee: An implied guarantee is a type of agreement in which the actions or conduct of the parties involved indicate that a guarantee exists without any written documentation. This type of guarantee can be difficult to prove in court as it is often based on interpretation of the parties` behavior.

In conclusion, while a contract of guarantee is an important legal document that outlines the terms and conditions of an agreement between parties, there are some exceptions to the requirement of writing in certain situations. It is important to be aware of these exceptions to ensure that you are fully informed when entering into a contract of guarantee.