Rails: Copyright headers for GPLv3 application

Question

We are developing a project in Rails and planning to open source it under GPLv3.

I have the following questions regarding this:

1. To which files should we add the copyright header? Only the .rb files in lib, controller, model, helpers, config etc? How about the .erb, .js, and .css files?
2. Should we add the detailed GPLv3 header to the source files? Or a few liner with a pointer to some external file in the project or a URL to GPL site would be suffice?

I have looked into a couple of open source projects developed in Rails. Some of them have added the copyright header in .rb files. Few have added in some other file type too.

This could be a matter of preference, but I am looking for best practices in this regard.

Thanks for your help.

Answer 1

Typical practice is to simply include a single LICENSE file at the top directory of the application, containing the full license text and any addendums. It's also common to include the license text or a link to it on the home page of the project (see many GitHub open source projects for examples). I'm not a lawyer, so I can't say how protections vary if you only include a single top-level license vs. a copyright notice in every file, but in practice you'll rarely see it all over the place.