The coverage form says what is insured; the causes of loss form says what it is insured against. Three ISO forms set the perils, and the insured picks one.

Basic and broad are named perils forms: a loss must fit a listed peril. The basic form lists perils such as fire, lightning, explosion, windstorm or hail, smoke, aircraft or vehicles, riot or civil commotion, vandalism, sprinkler leakage, sinkhole collapse and volcanic action. The broad form keeps those and adds falling objects; weight of snow, ice or sleet; and water damage. Example: a roof that collapses under the weight of ice is covered under broad but not basic.

The special form takes the open perils approach: it covers direct physical loss unless the policy excludes or limits it. So a loss that no named form lists, such as theft by burglars, can be covered under special. Open perils does not mean everything is covered; earth movement, water and many other causes remain excluded.

Where to look for exclusions: the CDI outline notes that most of the exclusions of a commercial property policy are contained in the causes of loss form. The BPP form describes the property and how a loss is valued, the declarations show limits and which forms apply, and the Common Policy Conditions deal with matters such as cancellation and premiums.