On the surface it would seem like you're correct, but only so in some cases. If for example you're running Linux on a Macbook Air you have no eth0 by default.

On the surface it would seem like you're correct, but only so in some cases. If for example you're running Linux on a Macbook Air you have no eth0 by default. Ergo, documentation referencing it is technically incorrect - it would be possible to say badly written at this point but that's even more pedantic than your comment ;)