14677522_ser_Agent_Implementation_Guide_events_to_be_fired_in_each_API_ATK_AT_SPI_event
[Scenario] When an accessibility subtree is shown [MSAA] EVENT_OBJECT_SHOW [Mac OS X Notification] AXUIElementCreated If in a live region, AXLiveRegionChanged [ATK/AT-SPI event] 
children_changed::add
WAI-ARIA 1.0 User Agent Implementation Guide