diff --git a/src/tree_schema.h b/src/tree_schema.h
index da73da2..b7a8c5d 100644
--- a/src/tree_schema.h
+++ b/src/tree_schema.h
@@ -699,42 +699,46 @@
  *     1 - container    6 - anydata/anyxml    11 - identity
  *     2 - choice       7 - case              12 - extension
  *     3 - leaf         8 - notification      13 - bitenum
- *     4 - leaflist     9 - rpc
- *     5 - list        10 - feature
+ *     4 - leaflist     9 - rpc/action        14 - when
+ *     5 - list        10 - feature           15 - must
  *
- *                                             1 1 1 1
- *     bit name              1 2 3 4 5 6 7 8 9 0 1 2 3
- *     ---------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       1 LYS_CONFIG_W     |x|x|x|x|x|x|x| | | | | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       2 LYS_CONFIG_R     |x|x|x|x|x|x|x| | | | | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       3 LYS_STATUS_CURR  |x|x|x|x|x|x|x|x|x|x|x|x| |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       4 LYS_STATUS_DEPRC |x|x|x|x|x|x|x|x|x|x|x|x| |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       5 LYS_STATUS_OBSLT |x|x|x|x|x|x|x|x|x|x|x|x| |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       6 LYS_MAND_TRUE    |x|x|x|x|x|x| | | | | | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       7 LYS_ORDBY_USER   | | | |x|x| | | | | | | | |
- *         LYS_MAND_FALSE   | |x|x| | |x| | | | | | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       8 LYS_ORDBY_SYSTEM | | | |x|x| | | | | | | | |
- *         LYS_PRESENCE     |x| | | | | | | | | | | | |
- *         LYS_UNIQUE       | | |x| | | | | | | | | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *       9 LYS_KEY          | | |x| | | | | | | | | | |
- *         LYS_FENABLED     | | | | | | | | | |x| | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *      10 LYS_SET_DFLT     | | |x|x| | |x| | | | | | |
- *         LYS_ISENUM       | | | | | | | | | | | | |x|
- *         LYS_KEYLESS      | | | | |x| | | | | | | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *      11 LYS_SET_UNITS    | | |x|x| | | | | | | | | |
- *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+
- *      12 LYS_SET_CONFIG   |x|x|x|x|x|x| | | | | | | |
- *     ---------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *                                             1 1 1 1 1 1
+ *     bit name              1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+ *     ---------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       1 LYS_CONFIG_W     |x|x|x|x|x|x|x| | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       2 LYS_CONFIG_R     |x|x|x|x|x|x|x| | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       3 LYS_STATUS_CURR  |x|x|x|x|x|x|x|x|x|x|x|x| | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       4 LYS_STATUS_DEPRC |x|x|x|x|x|x|x|x|x|x|x|x| | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       5 LYS_STATUS_OBSLT |x|x|x|x|x|x|x|x|x|x|x|x| | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       6 LYS_MAND_TRUE    |x|x|x|x|x|x| | | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       7 LYS_ORDBY_USER   | | | |x|x| | | | | | | | | | |
+ *         LYS_MAND_FALSE   | |x|x| | |x| | | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       8 LYS_ORDBY_SYSTEM | | | |x|x| | | | | | | | | | |
+ *         LYS_PRESENCE     |x| | | | | | | | | | | | | | |
+ *         LYS_UNIQUE       | | |x| | | | | | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *       9 LYS_KEY          | | |x| | | | | | | | | | | | |
+ *         LYS_FENABLED     | | | | | | | | | |x| | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *      10 LYS_SET_DFLT     | | |x|x| | |x| | | | | | | | |
+ *         LYS_ISENUM       | | | | | | | | | | | | |x| | |
+ *         LYS_KEYLESS      | | | | |x| | | | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *      11 LYS_SET_UNITS    | | |x|x| | | | | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *      12 LYS_SET_CONFIG   |x|x|x|x|x|x| | | | | | | | | |
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *      13 LYS_XPATH_DEP    |x|x|x|x|x|x|x|x| | | | | |x|x|
+ *                          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *      14 LYS_LEAFREF_DEP  | | |x|x| | | | | | | | | | | |
+ *     ---------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *
  */
 
@@ -796,6 +800,9 @@
 #define LYS_SET_UNITS    0x0400      /**< flag to know if the leaf's/leaflist's units are their own (flag set) or it is taken from the type. */
 #define LYS_SET_CONFIG   0x0800      /**< flag to know if the config property was set explicitly (flag set) or it is inherited. */
 
+#define LYS_XPATH_DEP    0x1000      /**< flag for nodes with when/must with external data dependency. */
+#define LYS_LEAFREF_DEP  0x2000      /**< flag for leaves(-lists) with leafref with external dependency. */
+
 #define LYS_SINGLEQUOTED 0x100       /**< flag for single-quoted argument of an extension instance's substatement, only when the source is YANG */
 #define LYS_DOUBLEQUOTED 0x200       /**< flag for double-quoted argument of an extension instance's substatement, only when the source is YANG */
 
@@ -1163,6 +1170,7 @@
     const char *ref;                 /**< reference */
     struct lysc_ext_instance *exts;  /**< list of the extension instances ([sized array](@ref sizedarrays)) */
     uint32_t refcount;               /**< reference counter since some of the when statements are shared among several nodes */
+    uint16_t flags;                  /**< [schema node flags](@ref snodeflags) - only LYS_XPATH_DEP is allowed */
 };
 
 /**
@@ -1254,6 +1262,7 @@
     const char *emsg;                /**< error-message */
     const char *eapptag;             /**< error-app-tag value */
     struct lysc_ext_instance *exts;  /**< list of the extension instances ([sized array](@ref sizedarrays)) */
+    uint16_t flags;                  /**< [schema node flags](@ref snodeflags) - only LYS_XPATH_DEP is allowed */
 };
 
 struct lysc_type {
@@ -1339,7 +1348,7 @@
     struct lysc_type_plugin *plugin; /**< type's plugin with built-in as well as user functions to canonize or validate the value of the type */
     LY_DATA_TYPE basetype;           /**< Base type of the type */
     uint32_t refcount;               /**< reference counter for type sharing */
-    const char* path;                /**< target path */
+    const char *path;                /**< target path */
     struct lys_module *path_context; /**< module where the path is defined, so it provides context to resolve prefixes */
     struct lysc_type *realtype;      /**< pointer to the real (first non-leafref in possible leafrefs chain) type. */
     uint8_t require_instance;        /**< require-instance flag */
@@ -1732,6 +1741,13 @@
 int lysc_feature_value(const struct lysc_feature *feature);
 
 /**
+ * @brief Types of the different schema paths.
+ */
+typedef enum {
+    LYSC_PATH_LOG /**< Descriptive path format used in log messages */
+} LYSC_PATH_TYPE;
+
+/**
  * @brief Generate path of the given node in the requested format.
  *
  * @param[in] node Schema path of this node will be generated.
@@ -1742,7 +1758,7 @@
  * @return NULL in case of memory allocation error, path of the node otherwise.
  * In case the @p buffer is NULL, the returned string is dynamically allocated and caller is responsible to free it.
  */
-char *lysc_path(struct lysc_node *node, LY_PATH_TYPE pathtype, char *buffer, size_t buflen);
+char *lysc_path(const struct lysc_node *node, LYSC_PATH_TYPE pathtype, char *buffer, size_t buflen);
 
 /**
  * @brief Available YANG schema tree structures representing YANG module.