...

• self (deprecated) - the underlying dynObj of the triggering object
• oSelf (deprecated) - the underlying controller of the triggering object
• eventSource - the object on which the event is triggered
• eventOrigin - the container from where the current screen was launched

The code implementation for centralized client logic is covered here: How to write centralized events

Decentralized client logic: (SWAT 22.13.0+)

...

EventNamespace: '#'
EventAttribute: '$ #.function(eventSource);'

The code implementation for decentralized client logic is covered here: How to write decentralized events

To maintain backwards compatibility with the centralized client logic and to avoid redundant import checks, the decentralized client logic handling is activated only when an event namespace is assigned to the object master.
The event namespace needs to be assigned at object master level and, afterwards, it can be referenced within the master itself. (master-level, instance-level, menu-level).