diff --git a/docs/source/format/CDataInterface/PyCapsuleInterface.rst b/docs/source/format/CDataInterface/PyCapsuleInterface.rst index 6da3ff28df75d..34e23edac1eec 100644 --- a/docs/source/format/CDataInterface/PyCapsuleInterface.rst +++ b/docs/source/format/CDataInterface/PyCapsuleInterface.rst @@ -266,7 +266,8 @@ protocol (e.g. only add ``__arrow_c_device_array__``, and not add ``__arrow_c_ar Producers that have data structures that can live both on CPU or non-CPU devices can implement both versions of the protocol, but the CPU-only versions (:meth:`__arrow_c_array__` and :meth:`__arrow_c_stream__`) should be guaranteed -to contain valid pointers for CPU memory. +to contain valid pointers for CPU memory (thus, when trying to export non-CPU data, +either raise an error or make a to CPU memory). Producing the ``ArrowDeviceArray`` and ``ArrowDeviceArrayStream`` structures is expected to not involve any cross-device copying of data.