Since 1980 the United States Pharmacopeia and the National Formulary have been published under the same cover. Today, USP-NF contains legally recognized and scientifically valid standards of identity, strength, quality, purity, packaging and labeling for more than 3,500 drugs. NF also includes similar standards for more than 250 excipients, vitamins, minerals, and botanicals. Standards (monographs) for substances which have an FDA-approved use as a drug are published in USP. Monographs for substances which are considered to be primarily excipients, a vitamin, mineral, botanical, or herbal are published in NF, provided they have been established as safe. “USP Reference Standards” is not a separate document per se but instead are substances used with official test methods in analytical testing to demonstrate a drug or excipient’s identity, strength, quality and purity. Once final standards are published in USP-NF they are recognized as official and U.S. and state government agencies are authorized to enforce them to assure that pharmaceutical products marketed in the U.S. are in total compliance.