Cross-border tax recovery: certificate-based enforcement allows a foreign collector to recover and remit taxes subject to reciprocity. Section 228 authorised certificate-based cross-border tax recovery whereby an Assessing Officer could send a section 222 certificate to a foreign Collector to recover tax from property in that Collector's district; the receiving Collector would recover as for domestic certificates and remit recovered sums to the originating Assessing Officer after deducting expenses, and the provision operated only while reciprocal law existed in the other jurisdiction.