desktop-file-install question

[Neal Becker]

I'm planning an update for kdiff3.

The current package has:
desktop-file-install  --vendor fedora \
    --dir $RPM_BUILD_ROOT%{_datadir}/applications  \
    --add-category Development \
    --add-category X-Fedora \
    --delete-original \
        $RPM_BUILD_ROOT%{_datadir}/applnk/Development/kdiff3.desktop

The new kdiff3 release adds another:
/usr/share/applnk/.hidden/kdiff3plugin.desktop

Where/how should this be installed?