<schemalist> <schema id='base'> <key name='foo' type='s'> <default>'bar'</default> </key> <key name='ranged' type='i'> <range min='0' max='22'/> <default>10</default> </key> <key name='choice' type='s'> <choices> <choice value='a'/> <choice value='aaa'/> <choice value='aaaaa'/> </choices> <default>'aaaaa'</default> </key> </schema> <schema id='sub' extends='base'> </schema> <schema id='sub2' extends='base'> <override name='foo'>'baz'</override> <override name='ranged'>0</override> <override name='choice'>'aaa'</override> </schema> <schema id='sub3' extends='sub2'> <override name='foo'>'foo'</override> </schema> </schemalist>