When the Insurance Service Office, Inc. (“ISO”) – the organization that drafts the standardized forms used by most insurance companies – revised its standard additional insured endorsement in 2013, it was an open question what effect the revisions would have on the insurer’s duty to defend. The 2013 revision added a provision that, if additional insured coverage is required by separate contract, the insurance afforded to the additional insured under the policy endorsement would “not be broader than” that required by the contract. The exact meaning of the phrase “will not be broader than” remained uncertain, particularly in situations where the additional insured endorsement and the underlying contract contained conflicting language.