diff --git a/src/common.h b/src/common.h
index dc71b11..a3403b5 100644
--- a/src/common.h
+++ b/src/common.h
@@ -172,62 +172,64 @@
 /* default maximum characters to print in LY_VCODE_INCHILDSTMT */
 #define LY_VCODE_INSTREXP_MAXLEN 20
 
-#define LY_VCODE_INCHAR      LYVE_SYNTAX, "Invalid character 0x%x."
-#define LY_VCODE_INSTREXP    LYVE_SYNTAX, "Invalid character sequence \"%.*s\", expected %s."
-#define LY_VCODE_EOF         LYVE_SYNTAX, "Unexpected end-of-input."
-#define LY_VCODE_NTERM       LYVE_SYNTAX, "%s not terminated."
-#define LY_VCODE_NSUPP       LYVE_SYNTAX, "%s not supported."
-#define LY_VCODE_MOD_SUBOMD  LYVE_SYNTAX, "Invalid keyword \"%s\", expected \"module\" or \"submodule\"."
-#define LY_VCODE_TRAILING_MOD LYVE_SYNTAX, "Trailing garbage \"%.*s%s\" after module, expected end-of-input."
+#define LY_VCODE_INCHAR         LYVE_SYNTAX, "Invalid character 0x%x."
+#define LY_VCODE_INSTREXP       LYVE_SYNTAX, "Invalid character sequence \"%.*s\", expected %s."
+#define LY_VCODE_EOF            LYVE_SYNTAX, "Unexpected end-of-input."
+#define LY_VCODE_NTERM          LYVE_SYNTAX, "%s not terminated."
+#define LY_VCODE_NSUPP          LYVE_SYNTAX, "%s not supported."
+#define LY_VCODE_MOD_SUBOMD     LYVE_SYNTAX, "Invalid keyword \"%s\", expected \"module\" or \"submodule\"."
+#define LY_VCODE_TRAILING_MOD   LYVE_SYNTAX, "Trailing garbage \"%.*s%s\" after module, expected end-of-input."
 #define LY_VCODE_TRAILING_SUBMOD LYVE_SYNTAX, "Trailing garbage \"%.*s%s\" after submodule, expected end-of-input."
 
-#define LY_VCODE_INVAL_MINMAX LYVE_SEMANTICS, "Invalid combination of min-elements and max-elements: min value %u is bigger than the max value %u."
+#define LY_VCODE_INVAL_MINMAX   LYVE_SEMANTICS, "Invalid combination of min-elements and max-elements: min value %u is bigger than the max value %u."
+#define LY_VCODE_CIRC_WHEN      LYVE_SEMANTICS, "When condition of \"%s\" includes a self-reference (referenced by when of \"%s\")."
 
-#define LY_VCODE_INSTMT      LYVE_SYNTAX_YANG, "Invalid keyword \"%s\"."
-#define LY_VCODE_INCHILDSTMT LYVE_SYNTAX_YANG, "Invalid keyword \"%s\" as a child of \"%s\"."
-#define LY_VCODE_INCHILDSTMT2 LYVE_SYNTAX_YANG, "Invalid keyword \"%s\" as a child of \"%s\" - the statement is allowed only in YANG 1.1 modules."
+#define LY_VCODE_INSTMT         LYVE_SYNTAX_YANG, "Invalid keyword \"%s\"."
+#define LY_VCODE_INCHILDSTMT    LYVE_SYNTAX_YANG, "Invalid keyword \"%s\" as a child of \"%s\"."
+#define LY_VCODE_INCHILDSTMT2   LYVE_SYNTAX_YANG, "Invalid keyword \"%s\" as a child of \"%s\" - the statement is allowed only in YANG 1.1 modules."
 #define LY_VCODE_INCHILDSTMSCOMB LYVE_SYNTAX_YANG, "Invalid combination of keywords \"%s\" and \"%s\" as substatements of \"%s\"."
-#define LY_VCODE_DUPSTMT     LYVE_SYNTAX_YANG, "Duplicate keyword \"%s\"."
-#define LY_VCODE_DUPIDENT    LYVE_SYNTAX_YANG, "Duplicate identifier \"%s\" of %s statement."
-#define LY_VCODE_INVAL       LYVE_SYNTAX_YANG, "Invalid value \"%.*s\" of \"%s\"."
-#define LY_VCODE_MISSTMT     LYVE_SYNTAX_YANG, "Missing mandatory keyword \"%s\" as a child of \"%s\"."
-#define LY_VCODE_MISSCHILDSTMT LYVE_SYNTAX_YANG, "Missing %s substatement for %s%s."
-#define LY_VCODE_INORD       LYVE_SYNTAX_YANG, "Invalid keyword \"%s\", it cannot appear after \"%s\"."
-#define LY_VCODE_OOB         LYVE_SYNTAX_YANG, "Value \"%.*s\" is out of \"%s\" bounds."
-#define LY_VCODE_INDEV       LYVE_SYNTAX_YANG, "Deviate \"%s\" does not support keyword \"%s\"."
-#define LY_VCODE_INREGEXP    LYVE_SYNTAX_YANG, "Regular expression \"%s\" is not valid (\"%s\": %s)."
+#define LY_VCODE_DUPSTMT        LYVE_SYNTAX_YANG, "Duplicate keyword \"%s\"."
+#define LY_VCODE_DUPIDENT       LYVE_SYNTAX_YANG, "Duplicate identifier \"%s\" of %s statement."
+#define LY_VCODE_INVAL          LYVE_SYNTAX_YANG, "Invalid value \"%.*s\" of \"%s\"."
+#define LY_VCODE_MISSTMT        LYVE_SYNTAX_YANG, "Missing mandatory keyword \"%s\" as a child of \"%s\"."
+#define LY_VCODE_MISSCHILDSTMT  LYVE_SYNTAX_YANG, "Missing %s substatement for %s%s."
+#define LY_VCODE_INORD          LYVE_SYNTAX_YANG, "Invalid keyword \"%s\", it cannot appear after \"%s\"."
+#define LY_VCODE_OOB            LYVE_SYNTAX_YANG, "Value \"%.*s\" is out of \"%s\" bounds."
+#define LY_VCODE_INDEV          LYVE_SYNTAX_YANG, "Deviate \"%s\" does not support keyword \"%s\"."
+#define LY_VCODE_INREGEXP       LYVE_SYNTAX_YANG, "Regular expression \"%s\" is not valid (\"%s\": %s)."
 
-#define LY_VCODE_INSUBELEM2   LYVE_SYNTAX_YIN, "Invalid sub-elemnt \"%s\" of \"%s\" element - this sub-element is allowed only in modules with version 1.1 or newer."
-#define LY_VCODE_INVAL_YIN   LYVE_SYNTAX_YIN, "Invalid value \"%s\" of \"%s\" attribute in \"%s\" element."
-#define LY_VCODE_UNEXP_SUBELEM LYVE_SYNTAX_YIN, "Unexpected sub-element \"%.*s\" of \"%s\" element."
-#define LY_VCODE_INDEV_YIN   LYVE_SYNTAX_YIN, "Deviate of this type doesn't allow \"%s\" as it's sub-element."
-#define LY_VCODE_INORDER_YIN LYVE_SYNTAX_YIN, "Invalid order of %s\'s sub-elements \"%s\" can't appear after \"%s\"."
-#define LY_VCODE_OOB_YIN      LYVE_SYNTAX_YIN, "Value \"%s\" of \"%s\" attribute in \"%s\" element is out of bounds."
+#define LY_VCODE_INSUBELEM2     LYVE_SYNTAX_YIN, "Invalid sub-elemnt \"%s\" of \"%s\" element - this sub-element is allowed only in modules with version 1.1 or newer."
+#define LY_VCODE_INVAL_YIN      LYVE_SYNTAX_YIN, "Invalid value \"%s\" of \"%s\" attribute in \"%s\" element."
+#define LY_VCODE_UNEXP_SUBELEM  LYVE_SYNTAX_YIN, "Unexpected sub-element \"%.*s\" of \"%s\" element."
+#define LY_VCODE_INDEV_YIN      LYVE_SYNTAX_YIN, "Deviate of this type doesn't allow \"%s\" as it's sub-element."
+#define LY_VCODE_INORDER_YIN    LYVE_SYNTAX_YIN, "Invalid order of %s\'s sub-elements \"%s\" can't appear after \"%s\"."
+#define LY_VCODE_OOB_YIN        LYVE_SYNTAX_YIN, "Value \"%s\" of \"%s\" attribute in \"%s\" element is out of bounds."
 #define LY_VCODE_INCHILDSTMSCOMB_YIN LYVE_SYNTAX_YIN, "Invalid combination of sub-elemnts \"%s\" and \"%s\" in \"%s\" element."
-#define LY_VCODE_DUP_ATTR LYVE_SYNTAX_YIN, "Duplicit definition of \"%s\" attribute in \"%s\" element."
-#define LY_VCODE_UNEXP_ATTR LYVE_SYNTAX_YIN, "Unexpected attribute \"%.*s\" of \"%s\" element."
-#define LY_VCODE_MAND_SUBELEM LYVE_SYNTAX_YIN, "Missing mandatory sub-element \"%s\" of \"%s\" element."
-#define LY_VCODE_FIRT_SUBELEM LYVE_SYNTAX_YIN, "Sub-element \"%s\" of \"%s\" element must be defined as it's first sub-element."
-#define LY_VCODE_NAME_COL LYVE_SYNTAX_YIN, "Name collision between module and submodule of name \"%s\"."
-#define LY_VCODE_SUBELEM_REDEF LYVE_SYNTAX_YIN, "Redefinition of \"%s\" sub-element in \"%s\" element."
+#define LY_VCODE_DUP_ATTR       LYVE_SYNTAX_YIN, "Duplicit definition of \"%s\" attribute in \"%s\" element."
+#define LY_VCODE_UNEXP_ATTR     LYVE_SYNTAX_YIN, "Unexpected attribute \"%.*s\" of \"%s\" element."
+#define LY_VCODE_MAND_SUBELEM   LYVE_SYNTAX_YIN, "Missing mandatory sub-element \"%s\" of \"%s\" element."
+#define LY_VCODE_FIRT_SUBELEM   LYVE_SYNTAX_YIN, "Sub-element \"%s\" of \"%s\" element must be defined as it's first sub-element."
+#define LY_VCODE_NAME_COL       LYVE_SYNTAX_YIN, "Name collision between module and submodule of name \"%s\"."
+#define LY_VCODE_SUBELEM_REDEF  LYVE_SYNTAX_YIN, "Redefinition of \"%s\" sub-element in \"%s\" element."
 
-#define LY_VCODE_XP_EOE      LYVE_XPATH, "Unterminated string delimited with %c (%.15s)."
-#define LY_VCODE_XP_INEXPR   LYVE_XPATH, "Invalid character number %u of expression \'%s\'."
-#define LY_VCODE_XP_DUMMY    LYVE_XPATH, "Accessing the value of the dummy node \"%s\"."
-#define LY_VCODE_XP_EOF      LYVE_XPATH, "Unexpected XPath expression end."
-#define LY_VCODE_XP_INTOK    LYVE_XPATH, "Unexpected XPath token %s (%.15s)."
-#define LY_VCODE_XP_INFUNC   LYVE_XPATH, "Unknown XPath function \"%.*s\"."
-#define LY_VCODE_XP_INARGCOUNT LYVE_XPATH, "Invalid number of arguments (%d) for the XPath function %.*s."
-#define LY_VCODE_XP_INARGTYPE LYVE_XPATH, "Wrong type of argument #%d (%s) for the XPath function %s."
-#define LY_VCODE_XP_INCTX    LYVE_XPATH, "Invalid context type %s in %s."
-#define LY_VCODE_XP_DUMMY    LYVE_XPATH, "Accessing the value of the dummy node \"%s\"."
-#define LY_VCODE_XP_INOP_1   LYVE_XPATH, "Cannot apply XPath operation %s on %s."
-#define LY_VCODE_XP_INOP_2   LYVE_XPATH, "Cannot apply XPath operation %s on %s and %s."
-#define LY_VCODE_XP_INMOD    LYVE_XPATH, "Unknown module \"%.*s\"."
+#define LY_VCODE_XP_EOE         LYVE_XPATH, "Unterminated string delimited with %c (%.15s)."
+#define LY_VCODE_XP_INEXPR      LYVE_XPATH, "Invalid character number %u of expression \'%s\'."
+#define LY_VCODE_XP_EOF         LYVE_XPATH, "Unexpected XPath expression end."
+#define LY_VCODE_XP_INTOK       LYVE_XPATH, "Unexpected XPath token %s (%.15s)."
+#define LY_VCODE_XP_INFUNC      LYVE_XPATH, "Unknown XPath function \"%.*s\"."
+#define LY_VCODE_XP_INARGCOUNT  LYVE_XPATH, "Invalid number of arguments (%d) for the XPath function %.*s."
+#define LY_VCODE_XP_INARGTYPE   LYVE_XPATH, "Wrong type of argument #%d (%s) for the XPath function %s."
+#define LY_VCODE_XP_INCTX       LYVE_XPATH, "Invalid context type %s in %s."
+#define LY_VCODE_XP_DUMMY       LYVE_XPATH, "Accessing the value of the dummy node \"%s\"."
+#define LY_VCODE_XP_INOP_1      LYVE_XPATH, "Cannot apply XPath operation %s on %s."
+#define LY_VCODE_XP_INOP_2      LYVE_XPATH, "Cannot apply XPath operation %s on %s and %s."
+#define LY_VCODE_XP_INMOD       LYVE_XPATH, "Unknown module \"%.*s\"."
 
-#define LY_VCODE_DEV_NODETYPE LYVE_REFERENCE, "Invalid deviation of %s node - it is not possible to %s \"%s\" property."
+#define LY_VCODE_DEV_NODETYPE   LYVE_REFERENCE, "Invalid deviation of %s node - it is not possible to %s \"%s\" property."
 #define LY_VCODE_DEV_NOT_PRESENT LYVE_REFERENCE, "Invalid deviation %s \"%s\" property \"%s\" which is not present."
 
+#define LY_VCODE_NOWHEN         LYVE_DATA, "When condition \"%s\" not satisfied."
+
 /******************************************************************************
  * Context
  *****************************************************************************/