50 CFR 660.501 - Purpose and scope 2020 50 CFR 660.501 – Purpose and scope 2009 50 CFR 660.501 – Purpose and scope 2010 50 CFR 660.501 – Purpose and scope 2014 50 CFR 660.501 – Purpose and scope 2015 50 CFR 660.501 – Purpose and scope 2016 50 CFR 660.501 – Purpose and scope 2019 50 CFR 660.501 – Purpose and scope