I took a PDC course about a decade ago. Daaang! has it really been that long?
I filed a copy of my design and certificate with a place that kept records of such things. I thought it was filed with The Permaculture Research Institute, but I'm not finding the list of certificate holders on their site. Can someone help? If a missing certificate buried under 10 years of clickbait, misinformation, bot generated nonsense, and a broken G**gle isn't what was meant by PDC artifiacts, feel free to move this post to a more appropriate spot.
Maybe give them a call to see if you can get a copy of your certificate.
I would also suggest calling The Permaculture Research Institute to ask if what you are remembering even existed and if so, can you be directed as to where to find that.
I finally found it at permacultureglobal.org. (It was linked from PRI)
I took the PDC from PermaEthos which now seems defunct. Jack Spirko started it with a few other guys and Josiah Wallingford bought out the shares from the rest, but nothing really happened there after that except a few episodes of Permaculture Smackdown with Paul, and maybe the plant propagation course with Nick Ferguson.
Last time I accessed the site, I think I was able to access a full PDF of my design submission and the certificate. It shows a thumbnail of the project and a general description in my profile there, but I haven't been able to access the full PDF. I did just recently upgrade to a paid subscription to the platform.