From Fedora Project Wiki

Proposal: The section of the packaging guidelines on desktop-file-install usage should be amended 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