"U.S. Citizenship and Immigration Services (USCIS) makes decisions on benefit and service requests that not only affect foreign nationals and their future, but also the well-being of U.S. citizens, families, organizations, businesses, industries, localities, states, the nation, and international communities. Accordingly, USCIS strives to secure America's promise as a nation of immigrants by providing accurate and useful information to customers, promoting awareness and understanding of citizenship rights and responsibilities, and making adjudication decisions in a consistent and accurate manner that furthers the goals and integrity of our nation's immigration system. Our policies drive our benefit and services decisions and ensure that our guidance to USCIS officers who make those decisions reflects our agency's mission, and strategic vision. These policies also greatly affect our interaction with USCIS's diverse customer and stakeholder community. […] The USCIS Policy Manual provides transparency to our customers, including outlining policies that are easy to understand, while also furthering consistency, quality, and efficiency in our adjudications and customer service. The USCIS Policy Manual contains the official policies of USCIS and must be followed by all USCIS officers in the performance of their duties. The Policy Manual does not create any substantive or procedural right or benefit that is legally enforceable by any party against the United States or its agencies or officers or any other person."
U.S. Citizenship and Immigration Services: http://www.uscis.gov/