anchor.diff:    </div>
     <div class="field">
       <%= f.label :filesystem %><br>
  -    <%= f.select(:filesystem, MLOG_VOCAB["filesystems"].invert) %>
  +    <%= f.select(:filesystem, MLOG_VOCAB["filesystems"].invert, :include_blank => true ) %>
     </div>
     <div class="field">
       <%= f.label :has_dfxml %><br>
  
positive.code:   </div>
    <div class="field">
      <%= f.label :interface %><br>
      <%= f.select(:interface, MLOG_VOCAB["interfaces"].invert) %>
    </div>
    <div class="field">
      <%= f.label :imaging_software %><br>
      <%= f.select(:imaging_software, MLOG_VOCAB["imaging_software"].invert) %>
    </div>
    <div class="field">
      <%= f.label :hdd_interface %><br>
      <%= f.select(:hdd_interface, MLOG_VOCAB["hdd_interfaces"].invert) %>
    </div>
    <div class="field">
      <%= f.label :imaging_success %><br>
  
negative.code:   </div>
    <div class="field">
      <%= f.label :image_format %><br>
      <%= f.select(:image_format, MLOG_VOCAB["image_formats"].invert, :include_blank => true ) %>
  
    </div>
    <div class="field">
      <%= f.label :encoding_scheme %><br>
      <%= f.select(:encoding_scheme, MLOG_VOCAB["encoding_schemes"].invert, :include_blank => true ) %>
    </div>
    <div class="field">
      <%= f.label :partition_table_format %><br>
  