Notgeld (German for "emergency money" or "necessity money") was special money issued primarily in Germany and Austria to deal with economic crisis situations such as a shortage of small change or hyperinflation. It was not issued by the central bank (Reichsbank) but by various other institutions, e.g. town savings banks, municipalities, private and state-owned firms. It was therefore not legal tender, but rather a mutually-accepted means of payment in a particular locale or site.

Notgeld was mainly issued in the form of (paper) banknotes. Sometimes other forms were used, as well: coins, leather, silk, linen, stamps, aluminium foil, coal, and porcelain; there are also reports of elemental sulfur being used, as well as all sorts of re-used paper and carton material (e.g. playing cards). These pieces made from playing cards are extremely rare and are known as "Spielkarten", the German word for "playing card".

• Collecting German Notgeld
  notgeld.com
  Personal page of an English collector of German notgeld (1914-1923).
• Kurioses Notgeld
  das-deutsche-notgeld.de
  Unusual Notgeld from Germany Deutschland 1914-24.
• Notgeld - Emergency Money
  notafilia.com.br
  Site with general explanation about Notgeld, some scans and others. Portuguese and English.