Edit the selection list 'properties'

Select the Add property description button at the right bottom of the Properties tab of the Product data window. A new window will be displayed, where you can add or edit the Properties, displayed in the selection list.

Add a new property

Note
The most important rules for creating a new property are:
The description must be easy to find back for other users for detailed search criteria.
Try to reduce the number of properties in the database.
Add only the properties that are relevant for you company. 

Edit an existing document type

Delete a document type