gistfile1.txt

restrict = {
  :restriction => {
    :is_equal_to => [
      {
        :extended_field_uRI => {
          :distinguished_property_set_id => "PublicStrings",
          :property_name => 'tagspace',
          :property_type => "StringArray"
        }
      },
      :field_uRI_or_constant => { ## here I think
        :constant => {:value=>tag}
      }
    ]
  }
}