In addition to the system required mandatory fields, a selection of additional fields can be set as mandatory on a product. This gives users the control to make the fields mandatory for their own business needs.
How to set additional required fields
Open the Settings module and navigate to the Product Settings. Choose Edit to enable changes to be made. Locate the section Required Fields for New/Edited Products:

Enable the different fields with the respective sliders and choose Save to set those fields as required. This changes how products are handled within the Products module.
How does this change impact products
For products that have already been added prior to the required fields being changed, there will be no immediate change. Its only when those products are opened and edited that the newly set required fields will need to be filled in, if they haven’t been previously.
For products that are being added after the required fields have been changed, the newly specified required fields will need to be filled before the product can be added.
Importing products and additional required fields
When the fields are set as required, this impacts the Import process. Any field that has been set as required needs to be included in the import file.