+
+ # Three cases:
+ # 1: gl transaction (Dialogbuchung), invoice is false, no double split booking allowed
+
+ # 2: sales or vendor invoice (Verkaufs- und Einkaufsrechnung): invoice is
+ # true, instead of absumsatz use link AR/AP (there should only be one
+ # entry)
+
+ # 3. AR/AP transaction (Kreditoren- und Debitorenbuchung): invoice is false,
+ # instead of absumsatz use link AR/AP (there should only be one, so jump
+ # out of search as soon as you find it )
+
+ # case 1 and 2