How to Use Categories 
You can find the log categories in the following directory: <SAP_install_dir>/<system_name>/<instance_name>/j2ee/cluster/server<number>/log.
Category names are arranged hierarchically to reflect tasks and subtasks belonging together. Subcategories normally inherit properties of the parent category.
Caution
Categories are created by default from the SAP Logging API. You cannot create your own categories.
Currently the following top-level categories are available:
Archive
This category contains the archived log files.
Services
This category contains messages related to services tasks.
System
This category contains messages related to system operation tasks. It has the subcategories HttpaccessConfigChanges, Database, Logging, , SecuritySecurity_Audit, Server , and Userinterface to reflect the main entities.
Applications
This category contains messages related to application operation tasks.