REVENUE MEMORANDUM ORDER NO. 14-2013 issued on May 8, 2013 prescribes the revised office codes for the National Office and the Revenue Data Centers, in accordance with the approved BIR Rationalization Plan under Executive Order No. 366. All internal revenue documents/official papers must contain the office code of the preparing/originating office. The office code specified in the Order must be indicated at the lower left hand corner of an official document. .