Parameter points to an array of items.
NULL must not be passed as the value in, out, in-out; or as a return value.
NULL may be passed as the value in, out, in-out; or as a return value.
NULL may be passed instead of a pointer to a location.
Out parameter, where caller must allocate storage.
The intention of a Stable interface is to enable arbitrary third parties to develop applications to these interfaces, release them, and have confidence that they will run on all minor releases of the product (after the one in which the interface was introduced, and within the same major release). Even at a major release, incompatible changes are expected to be rare, and to have strong justifications.
The caller owns the data, and is responsible for free it.
The data is owned by the callee, which is responsible of freeing it.