In the 19th. century, Lloyd's and the Institute of London Underwriters (a grouping of London company insurers) developed between them standardised clauses for the use of marine insurance, and these have been maintained since. These are known as the Institute Clauses because the Institute covered the cost of their publication.
Within the overall guidance of the Marine Insurance Act and the Institute Clauses parties retain a considerable freedom to contract between themselves.
Marine insurance is the oldest type of insurance. Out of it grew non-marine insurance and reinsurance. It traditionally formed the majority of business underwritten at Lloyd's. Nowadays, Marine insurance is often grouped with Aviation and Transit (ie. cargo) risks, and in this form is known by the acronym 'MAT'.
[edit] Practice
The Marine Insurance Act includes, as a schedule, a standard policy (known as the 'SG form'), which parties were at liberty to use if they wished. Because each term in the policy had been tested through at least two centuries of judicial precedent, the policy was extremely thorough. However, it was also expressed in rather archaic terms. In 1991, the London market produced a new standard policy wording known as the MAR 91 form and using the Institute Clauses. The MAR form is simply a general statement of insurance; the Institute Clauses are used to set out the detail of the insurance cover. In practice, the policy document usually consists of the MAR form used as a cover, with the Clauses stapled to the inside. Typically each clause will be stamped, with the stamp overlapping both onto the inside cover and to other clauses; this practice is used to avoid the substitution or removal of clauses
