SAP ABAP Message Number 01 - 591 (01) is used by

• Class (1)
• Function Module (2)

#	Object Type	Object Name	Object Description	Package	Structure Package	Software Component
1	Function Module	SUSR_USER_BUFFERS_TO_DB	Benutzer: Puffer auf die DB schreiben	SUSR	BASIS	SAP_BASIS
2	Function Module	SUSR_USER_MAINT_WITH_DIALOG	User: Create with dialog	SUSR	BASIS	SAP_BASIS