The WKN, or Wertpapierkennnummer, (WKN, WPKN, WPK or simply Wert), is a German securities identification code. Six digits or capital letters (excluding I and O), no check digit.
There have been several changes in the WKN definition:
WKNs may be obsolete in future, since they may be replaced by International Securities Identification Numbers (ISIN).
ISIN can assist with getting your WKN.