My research

written_content.xml

    <struct-type type-name='written_content'
                 instance-vector='$global.world.written_contents.all' key-field='id'>
        <int32_t name='id'/>
        <int32_t comment='pages before?'/>
        <int32_t name='pages'/>
        <stl-vector name='general_refs' pointer-type='general_ref'/>
        <stl-vector type-name='int32_t'/>
        <int32_t/>
        <int32_t/>
        <int32_t/>
        <stl-vector name='styles' type-name='int32_t'/> some enum
        <stl-vector name='style_subtype' type-name='int32_t'/> also an enum
        <int32_t/>
        <int32_t/>
    </struct-type>