So in the process of booking our "Smoove" discount fares Koln-Paris, the DBahn website says "ticket with reservation obligation." Is there something else I will need to do? And why is the "product" a Thalys train?
Thalys is not a train of any national rail company. Thalys is a cooperative endeavor of the national rail companies of France, Belgium, Germany, and maybe Netherlands. I think tickets for Thalys trains always come with reservations. You can get tickets at www.thalys.com. If you book ahead, you can often get very good discounts. Sometimes you can also get tickets for an entire trip, including a Thalys leg, on the German Rail website.
The fare on DBahn is the same as through the Thalys website - 29euros pp. Thanks for the help.