title: ISO 7816 - tag list, header list and extended header list
body: <p>For my research project on university I got to implement a subset of ISO 7816-4 filesystem on Java Card based smart card. I read standard and implemented a couple features - dedicated files, transparent and record-oriented elementary files etc, been able to select files, some rudimentary access control.</p>
  
  <p>I am having difficulties to implement tag lists, header and extended header list. Standard is very succinct when describing usage of those data element for indirect data references.</p>
  
  <ul>
  <li>Tag list are used to return all objects having their tag in tag list (concatenation of tags without delimitation)</li>
  <li>header list is list of tag length values without delimitation</li>
  <li>extended header list also list of tag length values without delimitation used to get data</li>
  </ul>
  
  <p>Can someone explain where would you use these data elements referencing methods and provide some illustrative example of their usage, or point me to some literature where this is explained?
  Can header list have constructed tags in it?
  What is the difference between header and extended header list?
  With which ISO commands do you usually use these lists?</p>