Seat reservations Brussels to Basel

Booking train from Brussels to Basel on September 5th. The site shows trains are avialable and recommends seat reservations. When I get ready to book/confirm, it says "without reservation" where the coach and seat #s usually are. What does this mean exactly? There are two of us traveling. I'm finding this very confusing and frustrating. Thanks for your help.

Posted by Tom
Hüttenfeld, Hessen, Germany
9094 posts

We need more information. First of all, have you already bought tickets or are you using a railpass? Second, which "site" are you using? Third, which route are you taking, as there's more than one way to get from Basel to Brussels? If you're using the Deutsche Bahn site, it may be that part of your route involves a regional train, which usually do not sell reservations.