redmine/app/views/attachments/_form.rhtml

<span id="attachments_fields">
<%= file_field_tag 'attachments[1][file]', :size => 30, :id => nil  -%>
<%= text_field_tag 'attachments[1][description]', '', :size => 60, :id => nil %>
<em><%= l(:label_optional_description) %></em>
</span>
<br />
<small><%= link_to l(:label_add_another_file), '#', :onclick => 'addFileField(); return false;' %>
(<%= l(:label_max_size) %>: <%= number_to_human_size(Setting.attachment_max_size.to_i.kilobytes) %>)
</small>