In the example shown below, we chose to track the Purchase Unit of Measure for each Part. For each choice you would like the User to be able to select from, create one record in this setup table. The number of records you may enter is unlimited.
The entries in the example Custom Fields Table 1 below are the choices that will be available in a drop down menu in the Part record, on the tab labeled Custom Fields. Access to the Part Custom fields is controlled by User Group Security.