4.4 Copyright Notices

You should maintain a proper copyright notice and a license notice in each nontrivial file in the package. (Any file more than ten lines long is nontrivial for this purpose.) This includes header files and interface definitions for building or running the program, documentation files, and any supporting files. If a file has been explicitly placed in the public domain, then instead of a copyright notice, it should have a notice saying explicitly that it is in the public domain.

Even image files and sound files should contain copyright notices and license notices, if they can. Some formats do not have room for textual annotations; for these files, state the copyright and copying permissions in a README file in the same directory.

Change log files should have a copyright notice and license notice at the end, since new material is added at the beginning but the end remains the end.

When a file is automatically generated from some other file in the distribution, it is useful for the automatic procedure to copy the copyright notice and permission notice of the file it is generated from, if possible. Alternatively, put a notice at the beginning saying which file it is generated from.

A copyright notice looks like this:

     Copyright (C) year1, year2, year3  copyright-holder

The copyright-holder may be the Free Software Foundation, Inc., or someone else; you should know who is the copyright holder for your package.

Replace the `(C)' with a C-in-a-circle symbol if it is available. For example, use `@copyright{}' in a Texinfo file. However, stick with parenthesized `C' unless you know that C-in-a-circle will work. For example, a program's standard --version message should use parenthesized `C' by default, though message translations may use C-in-a-circle in locales where that symbol is known to work.

To update the list of year numbers, add each year in which you have made nontrivial changes to the package. (Here we assume you're using a publicly accessible revision control server, so that every revision installed is also immediately and automatically published.) When you add the new year, it is not required to keep track which files have seen significant changes in the new year and which have not. It is recommended and simpler to add the new year to all files in the package, and be done with it for the rest of the year.

For files which are regularly copied from another project (such as `gnulib'), the copyright notice should left as it is in the original.

Don't delete old year numbers, though; they can indicate when older versions might theoretically go into the public domain. If you copy a file into the package from some other program, keep the copyright years that come with the file.

Do not abbreviate the year list using a range; for instance, do not write `1996--1998'; instead, write `1996, 1997, 1998'.

The copyright statement may be split across multiple lines, both in source files and in any generated output. This often happens for files with a long history, having many different years of publication.

For an FSF-copyrighted package, if you have followed the procedures to obtain legal papers, each file should have just one copyright holder: the Free Software Foundation, Inc. You should edit the file's copyright notice to list that name and only that name.

But if contributors are not all assigning their copyrights to a single copyright holder, it can easily happen that one file has several copyright holders. Each contributor of nontrivial text is a copyright holder.

In that case, you should always include a copyright notice in the name of main copyright holder of the file. You can also include copyright notices for other copyright holders as well, and this is a good idea for those who have contributed a large amount and for those who specifically ask for notices in their names. (Sometimes the license on code that you copy in may require preserving certain copyright notices.) But you don't have to include a notice for everyone who contributed to the file (which would be rather inconvenient).

Sometimes a program has an overall copyright notice that refers to the whole program. It might be in the README file, or it might be displayed when the program starts up. This copyright notice should mention the year of completion of the most recent major version; it can mention years of completion of previous major versions, but that is optional.