- * The description of the image, or @c NULL if there is no such image, or @c NULL
- * if the specified image has no description.
+ * The description of the image, or @c NULL if there is no such image, or
+ * @c NULL if the specified image has no description. The description
+ * string is in library-internal memory and may not be modified or freed;
+ * in addition, the string will become invalid if the description of the
+ * image is changed, the image is deleted, or the ::WIMStruct is destroyed.