Local businesses might want to check their insurance policies before the G-20 delegates, as well as the expected protesters, convene here in three weeks.

Just as Hurricane Katrina victims learned their homeowners insurance didn't necessarily cover storm surge flooding, policies against property damage or lost business may not include losses associated with mass demonstrations.

Some things that seem obvious may not be. If protesters break a bank window, as they did at this spring's G-20 summit in London, property insurance policies almost certainly will cover the vandalism -- unless the policy excludes damage from civil riots.

Even under an "all-risk" policy, a unique event such as a G-20 summit can raise questions.

If a shop decides to board up its windows in anticipation of violent protests, is the cost covered? What if imposed security measures mean regular customers can't get to the business? Will the policy cover the lost business? What if the candy shop business is safe, but its primary supplier suffers heavy damage?

In one of the quirkier clauses found in some policies, there may be a coverage exclusion for "insurrections." Does a group of people marching against the summit constitute an insurrection-like rebellion, or simply a group of protesters voicing their views?

"Many businesses probably already have looked at their insurance policies to see what coverage may be available to them, and what steps they need to take," said Thomas Reiter, a K&L Gates attorney who specializes in representing corporate policy holders in insurance disputes.

As with the legal disputes arising after Hurricane Katrina, he said, "The lesson in either case is the importance of reviewing carefully the insurance policy wording that you have and not assuming, based on what you're told by others, that you are not covered."

In some cases, Mr. Reiter said, policies may cover more than businesses realize, including boarding up windows ahead of time, or safety concerns that scare away customers.

Loretta Worters disagreed on that point. The vice president for the Insurance Information Institute in New York says there's likely no legitimate claim without actual damage. Anticipatory costs -- the cost of boarding up storefront windows, for example -- would not be covered, she said. Nor are lost sales to a business located inside a security perimeter.

"It might be very tricky, but I don't think you would have coverage on that," she said. "You know the event is happening, so it's sort of like insuring a burning building. Insurance doesn't really cover for that kind of thing."

Businesses can insure against indirect losses, such as a key supplier's business being forced to close.

That requires a special addition to a policy, known as contingent business interruption insurance, although Lori Shaw, of insurance broker Aon Risk Services, says it is "a very common and traditional" addition for business insurance policies.

"They would need to check with their individual agent to verify what their policy covers," said Ms. Shaw, who works out of Charlotte, N.C. "It really depends on how large the business is and what other lines of coverage they have with the carrier."

Ms. Worters said such policies typically must be purchased on a yearly basis, and would not be available for shorter terms. At this point, Pittsburgh businesses might have trouble getting them at all until after the G-20.

Insurance is an important consideration given the sometimes violent history of world economic summits, most recently in London. The British paper, The Argus, reported the Royal Bank of Scotland has sued a lone, unemployed 17-year-old protester who was caught smashing computer equipment during the G-20 protests there in April, causing damage estimated at about $65,000. The protester has admitted following friends into the bank, but her attorney said she is responsible for only a small portion of the damage.

Financial institutions historically have been a target for protesters, as local institutions are well aware. But any steps they're taking to address are being kept under wraps.

Ron Gruendl, spokesman for BNY Mellon, said the company will not be commenting before the G-20 convenes "on matters relating to security, insurance issues and other related issues."

Spokespersons for PNC Financial Services and Dollar Bank also declined comment on their G-20 preparations and Citizens Bank did not respond to inquiries.