A feud letter ( or Absagebrief) was a document in which a feud was announced, usually with few words, in medieval Europe. The letter had to be issued three days in advance to be legally valid.
To prevent the feud from becoming a case of murder and thus become punishable by law, those involved had to abide by the following rules:
"Wettet, biscop Dierich van Moeres, dat wy den vesten Junker Johan can Cleve lever hebbet alls Juwe, unde wert Juwe hiermit affgesaget"<br>("Know this, Bishop Dietrich of Moers, that we prefer the steadfast Junker, John of Cleves, to you, and hereby give you notice thereof.")