18.5.3. Memory Management Rules
All state slots in a query have distinct values. With the exception of a reference parameter, no value is referenced twice. All state slot values can therefore be recursively freed independently of each other.
If a VSE returns data, this data must always be new, i.e. allocated inside the VSE and may not be a copy of or include any of the arguments as a substructure. All return values and arguments must be legitimate boxes and may not share a structure.