A

allow-none

NULL is ok, both for passing and for returning.

S

scope async

The callback is valid until first called.

T

transfer none

Don't free data after the code is done.

E

element-type

Generics and defining elements of containers and arrays.

T

transfer container

Free data container after the code is done.

transfer full

Free data after the code is done.

S

scope call

The callback is valid only during the call to the method.

scope notified

The callback is valid until the GDestroyNotify argument is called.