How does the PDX program work for USPTO design applications?

The USPTO attempts to retrieve foreign applications for design applications through the PDX program where possible. Specifically for Spanish industrial design applications:

The Spanish Patent and Trademark Office deposits certain ES industrial design applications for access by the USPTO via the WIPO DAS. Therefore, when the applicant claims foreign priority to an ES industrial design application and provides the WIPO DAS access code, the USPTO will attempt retrieval via the WIPO DAS.

This means that applicants claiming priority to Spanish industrial design applications should provide the WIPO DAS access code to enable the USPTO to retrieve the application through the WIPO Digital Access Service (DAS).