One more thing.. If I'll use some parts of Bootstrap for my project, is it mandatory to keep the copyright lines exactly as they're right now? If I'll write something like "Using Bootstrap <link>", is it okay?
For wordpress, there is already one header and I can't keep the same copyright header. And I will use just some parts of bootstrap, many other things will be coded by me manually, in the same stylesheet file. That's why I ask.
