After many years, there still is the occasional packager, who adds an explicit "Requires: %{name} = %{version}-%{release}" to a noarch -doc subpackage which contains files one can display with any suitable program (such as PDF, HTML or TXT files).
Thanks for your email Michael - I just checked my packages and found a few -javadoc packages that unnecessarily depend on the base package.
Regards,
Richard