Vejamos a estrutura do arquivo:
<?xml version="1.0" encoding="UTF-8"?>
<xfdesktop>
<upperbutton>/usr/share/desktop-directories/upperbutton.desktop</upperbutton>
<setting exec="">/usr/share/desktop-directories/Settings.directory</setting>
<help exec="">/usr/share/desktop-directories/help.directory</help>
<group>
<id>1</id>
<sequence>0</sequence>
<!--<directory_file title="" icon="" tag_background="/usr/share/backgrounds/images/blue-bk-title.png">/usr/share/desktop-directories/Internet.directory</directory_file>-->
<directory_file exec="" tag_background="/usr/share/backgrounds/images/home-blue-title.png">/usr/share/desktop-directories/Connect.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/blue-bk.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/blue-more.desktop</app>
</group>
<group>
<id>2</id>
<sequence>1</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/home-orange-title.png">/usr/share/desktop-directories/Works.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/orange-bk.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/orange-more.desktop</app> </group>
<group>
<id>3</id>
<sequence>2</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/home-yellow-title.png">/usr/share/desktop-directories/Fun.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/yellow-bk.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/yellow-more.desktop</app></group>
<group>
<id>4</id>
<sequence>3</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/home-green-title.png">/usr/share/desktop-directories/Files.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/green-bk.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/green-more.desktop</app> </group>
<group>
<id>5</id>
<sequence>4</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/blue-bk-title.png">/usr/share/desktop-directories/Connect.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/blue-bk-large.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/blue-back.desktop</app>
<app sequence="2" acs="email">/usr/share/applications/AME.desktop</app>
<app sequence="1" acs="im">/usr/share/applications/acerim.desktop</app>
<app sequence="0">/usr/share/applications/linpus-web.desktop</app>
<!--app sequence="7">/usr/share/applications/skype.desktop</app-->
<!-- <app sequence="5">/usr/share/applications/luvcview.desktop</app>-->
<!-- <app icon="ftp.png" name="FTP" sequence="5">/usr/share/applications/net-gftp.desktop</app>-->
<!-- <app sequence="5" acs="rss">/usr/share/applications/acerrss.desktop</app> -->
<app sequence="3">/usr/share/applications/acerrss.desktop</app>
<app sequence="5">/usr/share/applications/edesktop/googlemap.desktop</app>
<app sequence="4">/usr/share/applications/edesktop/wikipedia.desktop</app>
<app sequence="6">/usr/share/applications/edesktop/webmail.desktop</app>
<app sequence="7">/usr/share/applications/MobilePartner.desktop</app></group>
<group>
<id>6</id>
<sequence>5</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/orange-bk-title.png">/usr/share/desktop-directories/Works.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/orange-bk-large.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/orange-back.desktop</app>
<app sequence="0">/usr/share/applications/openoffice.org-1.9-writer.desktop</app>
<app sequence="1">/usr/share/applications/openoffice.org-1.9-calc.desktop</app>
<app sequence="2">/usr/share/applications/openoffice.org-1.9-impress.desktop</app>
<app sequence="3">/usr/share/applications/acercalendar.desktop</app>
<app sequence="4">/usr/share/applications/acercontact.desktop</app>
<!--app icon="burning.png" name="CD/DVD Burning" sequence="6">/usr/share/applications/gnome-gcalctool.desktop</app>
<app sequence="6">/opt/Adobe/Reader8/Resource/Support/AdobeReader.desktop</app>-->
<app sequence="5">/usr/share/applications/galculator.desktop</app>
<!--app sequence="8">/usr/share/applications/gnome-dictionary.desktop</app-->
<!-- <app icon="snapshot.png" name="Snapshot" sequence="10">/usr/share/applications/gnome-screenshot.desktop</app>-->
<app sequence="6">/usr/share/applications/xpad.desktop</app>
<app sequence="7">/opt/Adobe/Reader8/Resource/Support/AdobeReader.desktop</app><app sequence="8">/usr/share/applications/gnome-screenshot.desktop</app></group>
<group>
<id>7</id>
<sequence>6</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/yellow-bk-title.png">/usr/share/desktop-directories/Fun.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/yellow-bk-large.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/yellow-back.desktop</app>
<app sequence="0">/usr/share/applications/pcmmvp.desktop</app>
<app sequence="1">/usr/share/applications/pcmphoto.desktop</app>
<!--<app icon="games.png" name="Games" sequence="4">/usr/share/applications/tuxpuck.desktop</app>-->
<dir sequence="2" dir_id="1">/usr/share/desktop-directories/Games.directory</dir>
<app sequence="3">/usr/share/applications/ucview.desktop</app>
<!--app icon="voice_recorder.png" name="Voice Recorder" sequence="9">/usr/share/applications/realplay.desktop</app-->
<app sequence="4">/usr/share/applications/kolourpaint.desktop</app>
<!-- <app icon="internetradio.png" name="Internet Radio" sequence="11">/usr/share/applications/realplay.desktop</app>
<app icon="picture.png" sequence="12">/usr/share/applications/gthumb.desktop</app>-->
</group>
<group>
<id>8</id>
<sequence>7</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/green-bk-title.png">/usr/share/desktop-directories/Files.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/green-bk-large.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/green-back.desktop</app>
<app sequence="1">/usr/share/applications/Document.desktop</app>
<app sequence="4">/usr/share/applications/Picture.desktop</app>
<app sequence="3">/usr/share/applications/Music.desktop</app>
<app sequence="5">/usr/share/applications/Video.desktop</app>
<app sequence="2">/usr/share/applications/Download.desktop</app>
<app sequence="0">/usr/share/applications/Thunar.desktop</app> </group>
<group>
<id>9</id>
<sequence>8</sequence>
<directory_file exec="" icon="" tag_background="/usr/share/backgrounds/images/gray-bk-title.png">/usr/share/desktop-directories/Settings.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/gray-bk-large.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/settings-back.desktop</app>
<app sequence="6">/usr/share/applications/gsynaptics.desktop</app>
<app sequence="5">/usr/share/applications/system-config-date.desktop</app>
<app sequence="8">/usr/share/applications/linpus-printconf-gui.desktop</app>
<app sequence="0">/usr/share/applications/xfce-display-settings.desktop</app>
<app sequence="4">/usr/share/applications/sysinfo.desktop</app>
<app sequence="7">/usr/share/applications/onlineupdate.desktop</app>
<app sequence="10">/usr/share/applications/redhat-userpasswd.desktop</app>
<app sequence="11">/usr/share/applications/keyboard_layout.desktop</app>
<app sequence="2">/usr/share/applications/networkcenter.desktop</app>
<app sequence="3">/usr/share/applications/audio.desktop</app>
<app sequence="1">/usr/share/applications/powercenter.desktop</app>
<app sequence="9">/usr/share/applications/linpus-scim-setup.desktop</app>
</group>
<dir id="1" parent_dir_id="0">
<directory_file exec="" tag_background="/usr/share/backgrounds/images/yellow-bk-title.png">/usr/share/desktop-directories/FunGames.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/yellow-bk-large-games.png</background_picture>
<!--> <app sequence="0">/usr/share/applications/linpus-circuslinux.desktop</app><-->
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/yellow-back.desktop</app>
<app sequence="0">/usr/share/applications/ltris.desktop</app>
<app sequence="1">/usr/share/applications/linpus-frozen-bubble.desktop</app>
<app sequence="2">/usr/share/applications/tuxpuck.desktop</app>
<app sequence="3">/usr/share/applications/llk_linux.desktop</app>
<app sequence="4">/usr/share/applications/supertux.desktop</app>
<app sequence="5">/usr/share/applications/bubbleshooter.desktop</app>
<app sequence="6">/usr/share/applications/ButterFlight.desktop</app>
<app sequence="7">/usr/share/applications/snooker.desktop</app>
<app sequence="8">/usr/share/applications/checkers.desktop</app>
<app sequence="9">/usr/share/applications/mahjong.desktop</app>
<app sequence="10">/usr/share/applications/volleyballey.desktop</app>
</dir>
</xfdesktop>
Além de configurar os "gráficos" (imagens de fundo e ícones) das "caixas" dos "Grupos", o arquivo em questão inclui as próprias aplicações, que precisam ter um arquivo "desktop" válido (que deve incluir um ícone também válido) em /usr/share/applications.
Isso quer dizer: se a aplicação está no menu do XFCE e tem um ícone válido naquele menu, ela pode ser colocada no "Acer Desktop" através de seu respectivo arquivo "desktop".
Mas para onde vai o "arquivo desktop"?
Primeiro, vejamos os nomes grupos em inglês, relacionados aos em português (de Portugal, já que não há tradução para o nosso):
- connect = ligar
- works = trabalho
- fun = diversão
- files = ficheiros
Assim temos o primeiro grupo de aplicações e seus ícones, o "Connnect" (id 5), reconhecido pelo uso do arquivo "Connect.directory" na terceira linha, mas que também poderia ser reconhecido pela cor usada (azul, que vem de "blue-bk-title.png") ou por conter as aplicações "wikipedia.desktop" e "webmail.desktop".
Aqui está ele:
<group>
<id>5</id>
<sequence>4</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/blue-bk-title.png">/usr/share/desktop-directories/Connect.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/blue-bk-large.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/blue-back.desktop</app>
<app sequence="2" acs="email">/usr/share/applications/AME.desktop</app>
<app sequence="1" acs="im">/usr/share/applications/acerim.desktop</app>
<app sequence="0">/usr/share/applications/linpus-web.desktop</app>
<!--app sequence="7">/usr/share/applications/skype.desktop</app-->
<!-- <app sequence="5">/usr/share/applications/luvcview.desktop</app>-->
<!-- <app icon="ftp.png" name="FTP" sequence="5">/usr/share/applications/net-gftp.desktop</app>-->
<!-- <app sequence="5" acs="rss">/usr/share/applications/acerrss.desktop</app> -->
<app sequence="3">/usr/share/applications/acerrss.desktop</app>
<app sequence="5">/usr/share/applications/edesktop/googlemap.desktop</app>
<app sequence="4">/usr/share/applications/edesktop/wikipedia.desktop</app>
<app sequence="6">/usr/share/applications/edesktop/webmail.desktop</app>
<app sequence="7">/usr/share/applications/MobilePartner.desktop</app></group>
A partir do reconhecimento da seção do arquivo que corresponde ao "Connect", será possível reconhecer as seções referentes ao grupo "Works", (Works.directory; orange-bk-title.png; aplicação "AdobeReader.desktop"):
<group>
<id>6</id>
<sequence>5</sequence>
<directory_file exec="" tag_background="/usr/share/backgrounds/images/orange-bk-title.png">/usr/share/desktop-directories/Works.directory</directory_file>
<background_picture>/usr/share/backgrounds/images/orange-bk-large.png</background_picture>
<app is_arrow="1" name="" sequence="-10">/usr/share/applications/orange-back.desktop</app>
<app sequence="0">/usr/share/applications/openoffice.org-1.9-writer.desktop</app>
<app sequence="1">/usr/share/applications/openoffice.org-1.9-calc.desktop</app>
<app sequence="2">/usr/share/applications/openoffice.org-1.9-impress.desktop</app>
<app sequence="3">/usr/share/applications/acercalendar.desktop</app>
<app sequence="4">/usr/share/applications/acercontact.desktop</app>
<!--app icon="burning.png" name="CD/DVD Burning" sequence="6">/usr/share/applications/gnome-gcalctool.desktop</app>
<app sequence="6">/opt/Adobe/Reader8/Resource/Support/AdobeReader.desktop</app>-->
<app sequence="5">/usr/share/applications/galculator.desktop</app>
<!--app sequence="8">/usr/share/applications/gnome-dictionary.desktop</app-->
<!-- <app icon="snapshot.png" name="Snapshot" sequence="10">/usr/share/applications/gnome-screenshot.desktop</app>-->
<app sequence="6">/usr/share/applications/xpad.desktop</app>
<app sequence="7">/opt/Adobe/Reader8/Resource/Support/AdobeReader.desktop</app><app sequence="8">/usr/share/applications/gnome-screenshot.desktop</app></group>
e também os demais, até porque vem na sequência:
- connect = ligar - <id>5</id>
- works = trabalho - <id>6</id>
- fun = diversão - <id>7</id>
- files = ficheiros - <id>8</id>