Message Class list used by SAP ABAP Class CL_KW_STR_TREE (Structure Tree)
SAP ABAP Class CL_KW_STR_TREE (Structure Tree) is using
# Object Type Object Name Object Description Note
     
1 Message Class  00 General Basis texts
2 Message Class  14 Task handler messages
3 Message Class  42 Information Workbench
4 Message Class  IWB_42 Enhancement for Message Class 42
5 Message Class  NR Number ranges