A model agreement hammered out by industry players representing listing portals, MLSs and brokerages in the hopes of standardizing the terms under which listings are provided to big search sites like Zillow, Trulia and realtor.com should be viewed as a floor, not a ceiling, says a prominent real estate industry consultant and attorney. Brian Larson, who advises brokers and MLSs, says the model content licensing agreement - drafted by Clareity Consulting, and offered by nonprofit real estate intellectual property protection group REDPLAN - is worth buying .