It's an instance of the SessionInfo class, basically an object containing some basic stuff like who you are, when you logged on, etc. OneStream passes it to every Main function defined on the Main class of every custom business rule; if inside that function you then invoke some other function or sub, you have to explicitly pass the object around.
Most BRApi calls will require it, in order to define whether you're actually allowed to perform this or that action.
Brilliant, thanks Jack - very clear, a good learning for me - always wondered what it meant!
