smarts are built by the (name recently changed) "Mercedes-Benz Cars Division" of Daimler AG. The M-B C Division builds four product lines: M-B, Maybach, Mercedes-AMG GmbH, and smart.
Daimler's "Daimler Trucks Division" builds Mercedes-Benz, Freightliner, Sterling, Western Star, Thomas, Detroit Diesel, and Mitsubishi* Fuso. A Detroit Diesel isn't a M-B.
Daimler's "Mercedes-Benz Vans Unit" builds Mercedes-Benz "models" Vario, Vito, Viano, and Sprinter (badged as Dodge** and Freightliner). Yup, in this case a Sprinter is a model of M-B Vans thus a M-B.
Daimler's "Daimler Buses Unit" builds the separete brands of Mercedes-Benz, Orion, and Setra. A Setra isn't a M-B; it is a Setra.
* Note DAG's connection with Mitsu, similar to their connection with the Mitsu Colt-based smart forfour, and our 3B21 engines.
**Daimler still retains some minor ownership in Chrysler, at least for now.
N.B.: Daimler reserves the tristar for M-B named brands, including Mercedes-AMG. The M-B Cars Division does not use a logo for the division, nor does Daimler AG for the corporation. DAG's standard is a simple white flag with Daimler in blue.