The Compliance Center computers are programmed to select those returns with high DIF scores which reflect issues that could be easily resolved by mail. The computers select those returns which are appropriate for correspondence audits and each respective return is reviewed by either a Tax examiner or clerk. The returns are DIF screened and quality reviewed using technically proficient examination personnel who are experienced in DIF screening operations. Returns which have apparent examination issues other than those appropriate for correspondence audit are referred to the local Area Office. Some examples of the kinds of items which can be verified by correspondence are itemized deductions, such as interest, taxes, contributions, medical expenses, and simple miscellaneous deductions such as union dues and small tools. Issues other than itemized deductions may be examined if they are single matters which would not be appropriate for office audit or field examination.