19.2.        Recommendation. As a general guideline, it is recommended that international merchandise trade statistics record all goods that add to or subtract from the stock of material resources of a country by entering (imports) or leaving (exports) its economic territory. The general guideline is subject to the clarifications provided in chapter I as well as other chapters of IMTS 2010 and, in particular, to the specific guidelines set out in IMTS 2010, chapter I, section B. 

19.3.        Interpretation of the general guideline. The recommendation establishes two criteria for the recording of goods. First, goods have to physically enter or leave the economic territory and, second, the goods need to add or subtract from the stock of material resources of a country. The interpretation of this general guideline depends on what is to be understood as a good, what is to be considered the economic territory, and what it means for goods to be part of the stock of material resources of a country. IMTS 2010 provides definitions of all three terms (IMTS 2010, paras. I.5 to I.7). The discussion of specific categories of goods in this and subsequent chapters of part four, on the compilation of data on trade in selected categories of goods, touches upon these three definitions.