Various conventional moisture regain

Usually, we are confused on the yarn weight difference during the business, some factory like to count the weight by net weight, but some like to count on conventional weight. What is the difference? In order to get a fair weight for both seller and buyer, there is a conventional moisture regain, based on this rate, the conventional weight is acceptable for every part. Here I list the conventional moisture regain for regular eco-friendly textile according to national standard GB/T 9994-2018: