More than 125 member facilities of the International Association of Conference Centers -- more than a third of the membership -- have signed on to support the organization's rigorous Code of Sustainability for 2010. Those who sign on must adhere to at least 75 percent of the 55 rules, which include tenets in nine areas: education and awareness, waste management, recycling, reuse, water conservation, purchasing, energy management, air quality and F&B. Those facilities that adhere to 75 percent of the tenets are called Silver Tier centers; those following 85 percent of the rules are Gold Tier; those reaching 100 percent are Platinum Tier. This year, four centers have reached the top tier. To see more on the code, click here.