It is necessary to paste the measurement status label. However, general quality inspection agencies often do not paste. The reason is that such labels are generally handwritten, which is a waste of time. You can buy this label from the store or print it yourself. Metrology institute may also sell it, which is very expensive. Musical instrument stores usually sell them cheaper. Then fill in and paste it yourself. As for the label content, you can find it on the general verification certificate. If there is no grading system for measuring instruments, buy a green "qualified" label. Both square and round are ok. About a few cents to a dime.