[adventured]

Legally, it's due to context of use.

eg Microsoft doesn't own my ability to use the word windows as it pertains to the physical objects I look out of my house through. I can start a window company, and use the word windows accordingly. We have the clearest, best windows, of any window manufacturer.

[sbi]

Thanks for explaining that to me. To add to the confusion, tabasco is also a pepper cultivar named after the Mexican state.