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HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <messagegroups>
      <group id="page-Bongo App" label="Bongo App" description="Translation of the wiki page [[:Bongo App|Bongo App]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Bongo Config" label="Bongo Config" description="Translation of the wiki page [[:Bongo Config|Bongo Config]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-CloudGate" label="CloudGate" description="Translation of the wiki page [[:CloudGate|CloudGate]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-CreateProject" label="CreateProject" description="Translation of the wiki page [[:CreateProject|CreateProject]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Developers API" label="Developers API" description="Translation of the wiki page [[:Developers API|Developers API]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-DevManual" label="DevManual" description="Translation of the wiki page [[:DevManual|DevManual]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-For Developers" label="For Developers" description="Translation of the wiki page [[:For Developers|For Developers]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-HDL" label="HDL" description="Translation of the wiki page [[:HDL|HDL]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-HowToBegin" label="HowToBegin" description="Translation of the wiki page [[:HowToBegin|HowToBegin]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Modbus" label="Modbus" description="Translation of the wiki page [[:Modbus|Modbus]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-ModuleTestAndApprove" label="ModuleTestAndApprove" description="Translation of the wiki page [[:ModuleTestAndApprove|ModuleTestAndApprove]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-PortForwarding" label="PortForwarding" description="Translation of the wiki page [[:PortForwarding|PortForwarding]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="!additions" label="Recent additions" description="This message group shows new and changed messages." class="RecentAdditionsMessageGroup" exists="" />
      <group id="!recent" label="Recent translations" description="This message group shows all recent translations into this language.&#10;Most useful for the review tasks." class="RecentMessageGroup" exists="" />
      <group id="page-Rpi" label="Rpi" description="Translation of the wiki page [[:Rpi|Rpi]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="!sandbox" label="Sandbox messages" description="Suggests messages to translate for sandboxed users" class="SandboxMessageGroup" exists="" />
      <group id="wiki-sidebar" label="Sidebar" description="Messages used in the sidebar of this wiki" class="WikiMessageGroup" exists="" />
      <group id="page-TestLite" label="TestLite" description="Translation of the wiki page [[:TestLite|TestLite]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-VoiceControl" label="VoiceControl" description="Translation of the wiki page [[:VoiceControl|VoiceControl]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-WorkingLite" label="WorkingLite" description="Translation of the wiki page [[:WorkingLite|WorkingLite]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Шаблон:API Function" label="Шаблон:API Function" description="Translation of the wiki page [[:Шаблон:API Function|Шаблон:API Function]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Шаблон:JSActionTable" label="Шаблон:JSActionTable" description="Translation of the wiki page [[:Шаблон:JSActionTable|Шаблон:JSActionTable]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Шаблон:JSConditionTable" label="Шаблон:JSConditionTable" description="Translation of the wiki page [[:Шаблон:JSConditionTable|Шаблон:JSConditionTable]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Шаблон:JSEventTable" label="Шаблон:JSEventTable" description="Translation of the wiki page [[:Шаблон:JSEventTable|Шаблон:JSEventTable]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
      <group id="page-Шаблон:Nat, Port Forwarding" label="Шаблон:Nat, Port Forwarding" description="Translation of the wiki page [[:Шаблон:Nat, Port Forwarding|Шаблон:Nat, Port Forwarding]] from русский (ru)." class="WikiPageMessageGroup" exists="" />
    </messagegroups>
  </query>
</api>