title: Inserting values for a classification system attribute via impex
body: <p>I have a classification system attribute in a classification class that classifies all categories in my catalog.</p>
  
  <p>This attribute is called Vanprijs. I can add values to this attribute for different products/variants on the hMC. Like on the picture below, but how can I add these values via impex files?</p>
  
  <p><img src="https://i.stack.imgur.com/3oOrI.jpg" alt="enter image description here"></p>
  
  <p>I did try this, but the importer doesn't recognize Vanprijs as a known attribute:</p>
  
  <pre><code>INSERT_UPDATE ModelVariantProduct;$baseProduct;code[unique=true];name[lang=$lang];Vanprijs;$catalogVersion;$approved
  ;B300047;M300047;Toiletverhoger (met deksel en stabiele armleuningen);10
  </code></pre>