Enter a code according to a classification system you have created. The field is alphanumeric. The classification and selection will also be alphanumeric. If the code consists of digits, it may be suitable to always use the same number of digits in the code. The classification will then be easier to comprehend, since 20 will appear before 100 when classifying. If you make a selection from 2 to 2, all the parts which have a code that starts will 2 will appear (2, 200, 2457 etc.).