contained values. Bugs involving concurrent incrementing or
decrementing of deference counts may be hard to track.
+The encoding functions (:func:`json_dumps()` and friends) track
+reference loops by modifying the internal state of objects and arrays.
+For this reason, encoding functions must not be run on the same JSON
+values in two separate threads at the same time. As already noted
+above, be especially careful if two arrays or objects share their
+contained values with another array or object.
+
+If you want to make sure that two JSON value hierarchies do not
+contain shared values, use :func:`json_deep_copy()` to make copies.
+
Locale
------