data tree BUGFIX clear type references and clarify lyd_dup validation status
Fixes #212
diff --git a/src/tree_data.h b/src/tree_data.h
index e2861e2..bd51c08 100644
--- a/src/tree_data.h
+++ b/src/tree_data.h
@@ -767,6 +767,11 @@
* @brief Create a copy of the specified data tree \p node. Namespaces are copied as needed,
* schema references are kept the same.
*
+ * The duplicated tree (the result) is created non-validated. To guarantee safe operations
+ * on it in the future, the recommended way of using it is after finishing all the partial data tree
+ * modifications, validate all the trees where the copies from this function were placed (or the copies
+ * themselves if they were kept separate).
+ *
* @param[in] node Data tree node to be duplicated.
* @param[in] recursive 1 if all children are supposed to be also duplicated.
* @return Created copy of the provided data \p node.