In September 2011, USCIS initiated a change in procedure where the agency would no longer issue original I-797A approval notices to a petitioner's or applicant's attorney. USCIS subsequently reverted to its original procedure of sending I-797A forms to attorneys in October 2011.
However, many individuals who did not receive their original I-797A approval notices were left with only the I-797C courtesy copy approval notice that was sent to the attorney. As result, there was some concern as to whether or not CBP would allow entry to the U.S. for individuals who only possessed this courtesy copy approval notice.
CBP has recently announced that individuals (e.g. Canadian TN visa workers who had filed for an extension of TN status, or change to TN status) who have only an I-797C courtesy copy approval notice may still be admitted to the U.S. by presenting this document. AILA / CBP Meeting, Nov. 9, 2011, AILA InfoNet Doc. 12020166 (Posted 02/01/12).