On June 29, 1999, we published the National Emission Standards for Hazardous Air Pollutants for Source Categories: Generic Maximum Achievable Control Technology (Generic MACT) Standards, which promulgated standards for four major hazardous air pollutants (HAP) source categories (i.e., acetal resins (AR) production, acrylic and modacrylic fiber (AMF) production, hydrogen fluoride (HF) production, and polycarbonate (PC) production). In September 1999, a petition for review of the June 1999 Generic MACT rule was filed by the General Electric Company in the U.S. Court of Appeals for the District of Columbia Circuit. The petitioner raised a concern regarding a recordkeeping provision in the promulgated rule. Subsequently, the petitioner raised an additional issue concerning the promulgated definition for "process vent," and identified some editorial, cross- reference, and wording errors. Pursuant to a settlement agreement, EPA has agreed to revisions addressing each of these issues. EPA is effectuating this agreement through a direct final rule because we consider these revisions to be noncontroversial, and we anticipate no adverse comment.