From Xojo Documentation
Returns a String array that contains a list of all of the methods in the stack from the main entrypoint to the point at which the exception was invoked.
The stack contains all the method names up and including the current method name.
This feature only works if the IncludeFunctionNames property on the App object is selected in the Shared Build Settings.
In addition to your own method calls, you will also see framework method calls, but these may not always be completely accurate due to insufficient symbols for the OS to resolve.