eHealth Infrastructure (v2019.5.2) 

{
  "resourceType" : "ValueSet",
  "id" : "correspondance-letter-identifier",
  "text" : {
    "status" : "generated",
    "div" : "<div xmlns=\"http://www.w3.org/1999/xhtml\"><h2>CorrespondanceLetterIdentifier</h2><div><p>Letter identifiers in correspondance messages are (alpha-numeric) serial numbers which are unique for the sending system. The sender must ensure that the same number is not used twice. Maximum length is 14 characters. Derived from http://svn.medcom.dk/svn/releases/Standarder/Den%20gode%20korrespondance/XML/Dokumentation/XDIS91.pdf, see 'BrevNr'</p>\n</div><p>This value set includes codes from the following code systems:</p><ul><li>Include all codes defined in <code>http://svn.medcom.dk/svn/releases/Standarder/Den%20gode%20korrespondance/XML/Dokumentation/XDIS91.pdf</code></li></ul></div>"
  },
  "url" : "http://ehealth.sundhed.dk/vs/correspondance-letter-identifier",
  "version" : "2019.5.2",
  "name" : "CorrespondanceLetterIdentifier",
  "status" : "draft",
  "experimental" : true,
  "date" : "2019-02-10T00:00:00+00:00",
  "publisher" : "FUT",
  "description" : "Letter identifiers in correspondance messages are (alpha-numeric) serial numbers which are unique for the sending system. The sender must ensure that the same number is not used twice. Maximum length is 14 characters. Derived from http://svn.medcom.dk/svn/releases/Standarder/Den%20gode%20korrespondance/XML/Dokumentation/XDIS91.pdf, see 'BrevNr'",
  "compose" : {
    "include" : [
      {
        "system" : "http://svn.medcom.dk/svn/releases/Standarder/Den%20gode%20korrespondance/XML/Dokumentation/XDIS91.pdf"
      }
    ]
  }
}