A
NULL is OK, both for passing and for returning.
E
Generics and defining elements of containers and arrays.
I
Parameter for input. Default is transfer none.
O
Parameter for returning results. Default is transfer full.
S
The callback is valid until first called.
The callback is valid only during the call to the method.
T
Free data container after the code is done.
Free data after the code is done.
Don't free data after the code is done.