@desktop, @elsedesktop, @enddesktop - for destkop devices
@handheld, @elsehandheld, @endhandheld - for non-desktop (mobile and tablet) devices
@tablet, @elsetablet, @endtablet - for tablet devices
@nottablet, @elsenottablet, @endnottablet - for non-tablet (desktop or mobile) devices
@mobile, @elsemobile, @endmobile - for mobile devices
@notmobile, @elsenotmobile, @endnotmobile - for non-mobile (desktop or tablet) devices
@ios, @elseios, @endios - for iOS platforms
@android, @elseandroid, @endandroid - for Android platforms
The usage of @else... directives are optional.