The drawing number is a field used to create a link between the drawing number and the part number, if they are not the same.
When working with manufacturing orders, the drawing number is printed if that option has been checked in the Manufacturing Order Documents procedure in the Global Settings procedure.
The drawing number can be included in the customer and purchase order rows. This is determined by the setting Show Part's Drawing Number on Customer Orders/Quotes?, under the section Orders /Quotes under the Sales tab, as well as the setting Show Part's Drawing Number on Orders/Inquiries?, under the section Orders / Inquiries under the Purchase tab in the Settings procedure.
The drawing number is a powerful search tool in the system, as there is an alternate PopUp feature that you open with the shortcut key F3 where you can search for drawing numbers in many important part number fields.
If you have installed the supplement Document Viewing, drawing files of a part can be linked by using the Document Viewer button next to the Comment... button under the Manufacturing tab.