Contracts which must be under seal

Contracts which must be under seal. 

This is a contract drawn and sealed by a party and submitted to the other for signature. Such is a contract requires on consideration. Example include lease agreement, charge, mortgage.

Contracts which must be in writing. 

This is a contract which must be embodied in a formal document. The law insists that it must be written. Examples include, hire purchase agreement, contract of marine insurance.

Contracts which must be evidenced in writing

This is a contract which must be evidenced by some note or memorandum. The law does not prescribe the form of note or memorandum. Examples include:
Contracts of insurance other than marine,
 Contract of guarantee