The EPEL packaging page - https://fedoraproject.org/wiki/EPEL:Packaging - summarizes additional guidelines needed for EPEL packaging, due to the older versions of packaging tools used in RHEL releases compared to Fedora, such as the need to have a BuildRoot tag and to clear the %buildroot in %install.

However, the need for a %clean section is not mentioned on this page. This is instead mentioned in the Fedora Packaging guidelines where the %clean section is discussed:

http://fedoraproject.org/wiki/Packaging:Guidelines#.25clean

"The %clean section is not required for F-13 and above. Each package for F-12 and below (or EPEL 5) MUST have a %clean section, which contains rm -rf %{buildroot} (or $RPM_BUILD_ROOT)."

I suggest that the need for a %clean section for EPEL 5 is also mentioned on the EPEL packaging page in order to collect all EPEL specific guidelines in one place. As it is now it is easily overlooked.