In 1972, GAO issued "Standards for Audit of Governmental Organizations, Programs, Activities and Functions," better known as the "yellow book." This publication contained audit standards which must be followed by Federal auditors for audits of Federal organizations, programs, activities, functions, funds received by contractors, nonprofit organizations, and other external organizations. These standards relate to the scope and quality of audit effort and to the characteristics of professional and meaningful audit reports. The standards as issued in 1972 have proved to be sound and durable and have been generally accepted by all levels of government as well as by the accounting profession. For the 1981 edition, the standards have been revised to: (1) expand the explanations of some standards in response to questions concerning them; (2) separate the standards for financial and compliance audits from those for economy and efficiency audits and program results audits; (3) incorporate standards relating to audits in which automatic data processing systems are used by the entity; and (4) add a standard to make more specific the auditor's responsibility for detecting fraud and abuse in government programs and operations.