app/views/search/_article_categories.html.erb
<div class="search-article-categories">
<div class="search-field-label"><%= _('Categories') %></div>
<span class="search-article-categories-container categories-cloud <%= "search-field-none" if article_categories.empty? %>">
<% article_categories.each do |category| %>
<%= link_to_category category, false, :class => "search-article-category" %>
<% end %>
<%= _('None') if article_categories.empty? %>
</span>
</div>