anchor.diff:  <%
  -  filter_by ||= [:title, :author, :world_location, :type, :state, :date]
  +  filter_by ||= [:title, :author, :organisation, :world_location, :type, :state, :date]
   %>
   <nav class="editions-filter">
     <h2>Filter list by:</h2>
  
positive.code:       <% end %>
      </div>
    <% end %>
    <% if filter_by.include?(:author) %>
      <div class="filter-grouping">
        <%= form_tag("", method: :get, class: "js-edition-select-filter", id: 'author_filter') do %>
          <%= label_tag :author %>
          <%= select_tag  :author,
  
negative.code:         <%= pass_through_filter_options_as_hidden_fields(@filter, :type, :state, :world_location, :from_date, :to_date) %>
          <%= submit_tag "Go", class: "btn js-hidden" %>
        <% end %>
      <% end %>
  
      <% if filter_by.include?(:world_location) %>
        <%= form_tag("", method: :get, class: "js-edition-select-filter", id: 'world_location_filter') do %>
          <% if filter_by.include?(:author) or filter_by.include?(:organisation) %>
            <%= label_tag :world_location, 'or world location' %>
          <% else %>
            <%= label_tag :world_location %>
          <% end %>
          <%= select_tag  :world_location,
                          options_for_select(admin_world_location_filter_options(current_user), @filter.options[:world_location]),
                          class: 'chzn-select',
  