Here we would like to draw your attention to DNO_CUST04 transaction code in SAP. As we know it is being used in the SAP CA-NO (Messages in CA) component which is coming under CA module (Cross Application).DNO_CUST04 is a transaction code used for Basic Notification: User Settings in SAP.
It comes under the package DNO.
Transaction DNO_CUST04 technical data table
| Tcode | DNO_CUST04 |
| Purpose | Basic Notification: User Settings |
| Module | CA |
| Component | CA-NO |
| SAP Package | DNO |
| Type | P |