One new feature introduced in NAV 2017 that is item attributes.
Item attributes You can add attributes to your inventory items that make it really easy to find the right product that your customer wants. You can define your own attribute types, such as color, country of manufacture, size, or product dimensions, and add them to your items as a supplement to the built-in item attribute types and values. Then, when you add items to sales and purchase documents, or just organize your items, you can view and filter on the attribute values to limit the list of items to choose from or take action on.
Also you can create you own attributes and can block the existing attributes if they are not required.
This is the one of the good enhancement i have gone through it in NAV 2017.