When abend occurs, following message is logged:

Abend <abend code> detected in transaction <transaction name> program <program name>

The abend code is assigned to URCODE. The first character of abend code is assigned to highest byte of URCODE, the second character is assigned to the second high byte, the third character is assigned to the third byte, and the last character of abend code is assigned to least byte of URCODE. The abend code is also filled in the field CX_ABENDCODE of FML buffer.