In the United States there are two main documents that pertain to energy. The main one is the model code International Energy Conservation Code (IECC), developed by the International Code Council. 47 states have adopted it, as well as the District of Columbia, Puerto Rico, and the U.S. Virgin Islands. The other is Standard 90.1, developed jointly by the American National Standards Institute (ANSI), the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE), and the Illuminating Engineering Society of North America (IESNA). Minnesota and Indiana have adopted Standard 90.1. California has instead developed their own energy code which exceeds the requirements of both the IECC and Standard 90.1. But just because a state or commonwealth adopted one or the other, the local jurisdictions may have their own changes or adopted 90.1. Although most have chosen the IECC, Standard 90.1 is still important since the IECC accepts 90.1 as a suitable means for showing compliance for commercial buildings. For data centers, the greater flexibility of 90.1 means that compliance may be met more easily.