This issue came up during the 1.6.0-RC4 vote. The following files do not have license headers. Technically, they are binary files, but they may be able to store license information in a metadata field.
Since they are not used in our documentation, and appear to be remnants of an older developer guide that we no longer generate, they should be removed.
If desired, they can be copied from the SCM history to a wiki or put on the website, in useful location.