Use
If problem situations occur in the system, the Online Service System (OSS) provides fast, effective help. In OSS, you can enter your questions to SAP directly and immediately receive an initial response. The OSS provides you with the same information that SAP itself uses for First Level Support.
When you save the message you entered, the terminology contained in the message is used for an automatic search in the notes database. The system displays a list of notes, which contain detailed descriptions of how to solve the problem.
First and Second Level Support workers use incoming customer messages to write Notes. R/3 developers also create Notes if they recognize any potential sources of problems or missing information.
Activities
There are different ways to start a search for notes. Several are listed below:

sapdba, brbackup, brarchive, brconnect, brrestore, restore, maxextents, offline redo logs, control file, stuck, archivelog, tape_size, expir_period, reorganisation, restart, ora<error number>, init.ora, init.sap, reconnect, ops$
You can download OSS Notes to your computer. This allows you to forward the message without having to enter the text again. Of course, you can also print out the texts you have downloaded.