TDS/TCS return authentication and mandatory virus checks required before uploading returns to the central TDS database. Computer Centres shall authenticate TDS/TCS returns on computer media, perform virus checks with certification, convert and decompress data per the TDS Information System user manual, upload data into the ORACLE TDS database after making Return Receipt Register entries, verify control totals against Form No. 27A, mark the RRR number on media, and retain media in safe custody; infected, corrupted, or invalid-media returns and those with invalid TANs must be rejected and referred back to the Assessing Officer for resubmission.