The Guide describes (correctly) that it is optional to have a URL with the source location physically visible on the product itself. However, if you ship a product it is compulsory to accompany it with the documentation/designs and this is not mentioned in the Guide.

• Add to the Guide that either the "hardware design source package" or, more practical, the Source location to the "hardware design source package" should be shipped together with the product. I.e., if the source location is not marked on the product itself, it should be in the accompanying documentation.