General: "Jumbo boom" -- is this what happens when a jumbo jet breaks the sound barrier? Find out in the GISTnet glossary at http://www.gistnet.com/sub/glossary/jumbo_boom.html. Customs Brokers and Importers: Are you knowledgeable about the different forms of "in-bond" transportation? See http://www.gistnet.com/sub/glossary/in-bond.html. Freight Forwarders/Exporters: Do you know what an "MTD" is? See http://www.gistnet.com/sub/glossary/mtd.html.