This thread has so much great info. Thanks for posting. I have an "Anniversary" black coupe, and I've found a lot of questionable info surrounding these cars. And yes, I had been told it was a "Silver Anniversary" car, but that clearly isn't the correct verbiage. The option code list for the '89 911s shows "098": "Anniversary model "25 years 911" (USA), Silver Metallic with Silk Gray all leather interior incl. special center console and Silk Gray silk-velour carpets"
But of course, it says they were all Silver Metallic -- which I'm pretty sure wasn't the case.
Amazing how hard it is to find the real facts on these things. But whatever you call it, it's a wonderful car in every respect -- except maybe the air conditioner.