Bar on subsequent settlement applications when prior settlement involved concealment penalty, conviction, or return to proper officer. An applicant is barred from applying for settlement under section 127B in relation to any other matter where an earlier settlement provided for a penalty for concealment of particulars of duty liability, the applicant is later convicted of an offence under the Act in relation to that case, or the Settlement Commission sends the case back to the proper officer; the explanation clarifies that concealment relates to concealment made from the officer of customs.