I propose to amend the section of the packaging guidelines on
desktop-file-install usage[1] as follows:

* Rename the sub-heading from "desktop-file-install" to ".desktop file
  installation and validation"

* Change the first sentence to:

<<
It is not simply enough to just include the .desktop file in the package,
one MUST run desktop-file-install OR desktop-file-validate in %install (and
have BuildRequires: desktop-file-utils), to help ensure .desktop file safety
and spec-compliance. desktop-file-install MUST be used if the package does
not install the file or there are changes desired to the .desktop file (such
as add/removing categories, etc).  desktop-file-validate MAY be used instead
if the .desktop file's content/location does not need modification.  Here
are some examples of usage:
>>

* Add the following example:

<<
  desktop-file-validate %{buildroot}/%{_datadir}/applications/foo.desktop
>>


[1] http://fedoraproject.org/wiki/Packaging/Guidelines#head-d559ee7363418a5840ce63090c608c991cd39ce6