Where can I find the definition of the data measures, such as customs value and landed duty paid value?

On the query design page, there are blue question marks that open dialogue boxes with definitions. On Step 2, there is a question mark near “Data to Report: Summable Measure”. This question mark opens a dialogue box with definitions for the summable variables such as customs value and landed duty paid value. Definitions for the summable values and quantities can also be found on Census’ website at https://www.census.gov/foreign-trade/reference/definitions/index.html .