diff --git a/CHANGELOG.md b/CHANGELOG.md
index 626022fe..aec816b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,23 @@
 
 ## 3.6.0 (Upcoming)
 
+### Major changes:
+### Minor changes:
+
+* Use <config> instead of <data> when save/load configuration to file. This
+enables saved files to be used as datastore without any editing. Thanks Matt.
+
+* Added Yang "extension" statement. This includes parsing unknown
+  statements and identifying them as extensions or not. However,
+  semantics for specific extensions must still be added.
+
+* Renamed ytype_id and ytype_prefix to yarg_id and yarg_prefix, respectively
+
+* Added cli_show_version()
+
+### Corrected Bugs
+
+
 ## 3.5.0 (12 February 2018)
 
 ### Major changes:
diff --git a/apps/cli/cli_show.c b/apps/cli/cli_show.c
index 85645413..13f58339 100644
--- a/apps/cli/cli_show.c
+++ b/apps/cli/cli_show.c
@@ -587,7 +587,14 @@ done:
 	xml_free(xt);
     return retval;
 }
+
 int show_confv_xpath(clicon_handle h, cvec *vars, cvec *argv)
 {
     return show_conf_xpath(h, vars, argv);
 }
+
+int cli_show_version(clicon_handle h, cvec *vars, cvec *argv)
+{
+    cli_output(stdout, "%s\n", CLIXON_VERSION_STRING);
+    return 0;
+}
diff --git a/example/example.yang b/example/example.yang
index 3c6a6f3a..f3c39917 100644
--- a/example/example.yang
+++ b/example/example.yang
@@ -1,10 +1,14 @@
 module example {
+    prefix ex;
     import ietf-ip {
-      prefix ip;
+	prefix ip;
     }
     import ietf-routing {
-      prefix rt;
+	prefix rt;
+    }
+    import ietf-netconf-acm {
+	prefix nacm; /* See RFC 6536 */
     }
     description
-      "Example code that includes ietf-ip and ietf-routing";
+	"Example code that includes ietf-ip and ietf-routing";
 }
diff --git a/example/routing_cli.c b/example/routing_cli.c
index b054d943..bdb621b7 100644
--- a/example/routing_cli.c
+++ b/example/routing_cli.c
@@ -81,7 +81,7 @@ mycallback(clicon_handle h, cvec *cvv, cvec *argv)
 
     /* Show eth0 interfaces config using XPATH */
     if (clicon_rpc_get_config(h, "running","/interfaces/interface[name=eth0]",
-			      &xret) < 0)
+			      NULL, &xret) < 0)
 	goto done;
 
     xml_print(stdout, xret);
diff --git a/example/routing_cli.cli b/example/routing_cli.cli
index 3c8a6a2d..63a285eb 100644
--- a/example/routing_cli.cli
+++ b/example/routing_cli.cli
@@ -30,6 +30,7 @@ compare("Compare running and candidate"), compare_dbs((int32)1);
 
 show("Show a particular state of the system"){
     xpath("Show configuration") <xpath:string>("XPATH expression"), show_conf_xpath("candidate");
+    version("Show version"), cli_show_version("candidate", "text", "/");
     compare("Compare candidate and running databases"), compare_dbs((int32)0);{
     		     xml("Show comparison in xml"), compare_dbs((int32)0);
 		     text("Show comparison in text"), compare_dbs((int32)1);
diff --git a/lib/clixon/clixon_yang.h b/lib/clixon/clixon_yang.h
index 084fe3c5..c89a8f80 100644
--- a/lib/clixon/clixon_yang.h
+++ b/lib/clixon/clixon_yang.h
@@ -114,6 +114,7 @@ enum rfc_6020{
     Y_TYPEDEF,
     Y_UNIQUE,
     Y_UNITS,
+    Y_UNKNOWN,
     Y_USES,
     Y_VALUE,
     Y_WHEN,
@@ -161,7 +162,9 @@ struct yang_stmt{
 					leaf-list, 
 					config: boolean true or false
 					mandatory: boolean true or false
-					fraction-digits for fraction-digits */
+					fraction-digits for fraction-digits
+					unkown-stmt (argument)
+				     */
     cvec              *ys_cvec;      /* List of stmt-specific variables 
 					Y_RANGE: range_min, range_max 
 					Y_LIST: vector of keys
@@ -206,8 +209,8 @@ yang_stmt *ys_dup(yang_stmt *old);
 int        yn_insert(yang_node *yn_parent, yang_stmt *ys_child);
 yang_stmt *yn_each(yang_node *yn, yang_stmt *ys);
 char      *yang_key2str(int keyword);
-char      *ytype_prefix(yang_stmt *ys);
-char      *ytype_id(yang_stmt *ys);
+char      *yarg_prefix(yang_stmt *ys);
+char      *yarg_id(yang_stmt *ys);
 yang_stmt *ys_module(yang_stmt *ys);
 yang_spec *ys_spec(yang_stmt *ys);
 yang_stmt *yang_find_module_by_prefix(yang_stmt *ys, char *prefix);
@@ -227,7 +230,7 @@ int        yang_abs_schema_nodeid(yang_spec *yspec, char *schema_nodeid,
 int        yang_desc_schema_nodeid(yang_node *yn, char *schema_nodeid, 
 				   yang_stmt **yres);
 cg_var    *ys_parse(yang_stmt *ys, enum cv_type cvtype);
-int        ys_parse_sub(yang_stmt *ys);
+int        ys_parse_sub(yang_stmt *ys, char *extra);
 int        yang_mandatory(yang_stmt *ys);
 int        yang_config(yang_stmt *ys);
 yang_spec *yang_spec_netconf(clicon_handle h);
diff --git a/lib/clixon/clixon_yang_type.h b/lib/clixon/clixon_yang_type.h
index 291766cf..61b581af 100644
--- a/lib/clixon/clixon_yang_type.h
+++ b/lib/clixon/clixon_yang_type.h
@@ -68,7 +68,6 @@ char      *cv2yang_type(enum cv_type cv_type);
 yang_stmt *yang_find_identity(yang_stmt *ys, char *identity);
 int        ys_cv_validate(cg_var *cv, yang_stmt *ys, char **reason);
 int        clicon_type2cv(char *type, char *rtype, enum cv_type *cvtype);
-char      *ytype_id(yang_stmt *ys);
 int        yang_type_get(yang_stmt *ys, char **otype, yang_stmt **restype, 
 			 int *options, cg_var **mincv, cg_var **maxcv, char **pattern,
                          uint8_t *fraction_digits);
diff --git a/lib/src/clixon_yang.c b/lib/src/clixon_yang.c
index 1014b0f0..ba3758b7 100644
--- a/lib/src/clixon_yang.c
+++ b/lib/src/clixon_yang.c
@@ -133,7 +133,8 @@ static const map_str2int ykmap[] = {
     {"type",             Y_TYPE}, 
     {"typedef",          Y_TYPEDEF}, 
     {"unique",           Y_UNIQUE}, 
-    {"units",            Y_UNITS}, 
+    {"units",            Y_UNITS},
+    {"unknown",          Y_UNKNOWN}, 
     {"uses",             Y_USES}, 
     {"value",            Y_VALUE}, 
     {"when",             Y_WHEN}, 
@@ -668,13 +669,15 @@ ys_spec(yang_stmt *ys)
     return (yang_spec*)ys;
 }
 
-/* Extract id from type argument. two cases:
- * argument is prefix:id, 
- * argument is id,        
+/* Assume argument is id on the type: <[prefix:]id>, return 'id'
  * Just return string from id
+ * @param[in] ys      A yang statement
+ * @retval    NULL    No id (argument is NULL)
+ * @retval    id      Pointer to identifier
+ * @see yarg_prefix
  */
 char*
-ytype_id(yang_stmt *ys)
+yarg_id(yang_stmt *ys)
 {
     char   *id;
     
@@ -685,13 +688,14 @@ ytype_id(yang_stmt *ys)
     return id;
 }
 
-/* Extract prefix from type argument. two cases:
- * argument is prefix:id, 
- * argument is id,        
- * return either NULL or a new prefix string that needs to be freed by caller.
+/* Assume argument is id on the type: <[prefix:]id>, return 'prefix'
+ * @param[in] ys      A yang statement
+ * @retval    NULL    No prefix
+ * @retval    prefix  Malloced string that needs to be freed by caller.
+ * @see yarg_id
  */
 char*
-ytype_prefix(yang_stmt *ys)
+yarg_prefix(yang_stmt *ys)
 {
     char   *id;
     char   *prefix = NULL;
@@ -822,7 +826,11 @@ yang_print_cbuf(cbuf      *cb,
     yang_stmt *ys = NULL;
 
     while ((ys = yn_each(yn, ys)) != NULL) {
-	cprintf(cb, "%*s%s", marginal, "", yang_key2str(ys->ys_keyword));
+	if (ys->ys_keyword == Y_UNKNOWN){ /* dont print unknown - proxy for extension*/
+	    cprintf(cb, "%*s", marginal-1, "");
+	}
+	else
+	    cprintf(cb, "%*s%s", marginal, "", yang_key2str(ys->ys_keyword));
 	if (ys->ys_argument){
 	    if (quotedstring(ys->ys_argument))
 		cprintf(cb, " \"%s\"", ys->ys_argument);
@@ -974,7 +982,7 @@ ys_populate_range(yang_stmt *ys,
 			  &options, NULL, NULL, NULL, &fraction_digits) < 0)
 	goto done;
     restype = yrestype?yrestype->ys_argument:NULL;
-    origtype = ytype_id((yang_stmt*)yparent);
+    origtype = yarg_id((yang_stmt*)yparent);
     /* This handles non-resolved also */
     if (clicon_type2cv(origtype, restype, &cvtype) < 0) 
 	goto done;
@@ -1291,8 +1299,8 @@ yang_expand(yang_node *yn)
 	switch(ys->ys_keyword){
 	case Y_USES:
 	    /* Split argument into prefix and name */
-	    name    = ytype_id(ys);     /* This is uses/grouping name to resolve */
-	    prefix  = ytype_prefix(ys); /* And this its prefix */
+	    name = yarg_id(ys);     /* This is uses/grouping name to resolve */
+	    prefix  = yarg_prefix(ys); /* And this its prefix */
 	    if (ys_grouping_resolve(ys, prefix, name, &ygrouping) < 0)
 		goto done;
 	    if (prefix)
@@ -2016,6 +2024,8 @@ ys_parse(yang_stmt   *ys,
  * Specific syntax checks  and variable creation for stand-alone yang statements.
  * That is, siblings, etc, may not be there. Complete checks are made in
  * ys_populate instead.
+ * @param[in] ys    yang statement
+ * @param[in] extra Yang extra for cornercases (unknown/extension)
  *
  * The cv:s created in parse-tree as follows:
  * fraction-digits : Create cv as uint8, check limits [1:8] (must be made in 1st pass)
@@ -2023,13 +2033,19 @@ ys_parse(yang_stmt   *ys,
  * @see ys_populate
  */
 int
-ys_parse_sub(yang_stmt *ys)
+ys_parse_sub(yang_stmt *ys,
+	     char      *extra)
 {
     int        retval = -1;
-    
+    int        cvret;
+    char      *reason = NULL;
+    yang_stmt *ymod;
+    uint8_t    fd;
+    char      *prefix = NULL;
+    char      *name;
+
     switch (ys->ys_keyword){
-    case Y_FRACTION_DIGITS:{
-	uint8_t fd;
+    case Y_FRACTION_DIGITS:
 	if (ys_parse(ys, CGV_UINT8) == NULL) 
 	    goto done;
 	fd = cv_uint8_get(ys->ys_cv);
@@ -2038,12 +2054,41 @@ ys_parse_sub(yang_stmt *ys)
 	    goto done;
 	}
 	break;
-    }
+    case Y_UNKNOWN:
+	if (extra == NULL)
+	    break;
+	/* Find extension, if found, store it as unknown, if not,
+	   break for error */
+	prefix  = yarg_prefix(ys); /* And this its prefix */
+	name    = yarg_id(ys);  /* This is the type to resolve */
+	if ((ymod = yang_find_module_by_prefix(ys, prefix)) == NULL)
+	    goto ok; /* shouldnt happen */
+	if (yang_find((yang_node*)ymod, Y_EXTENSION, name) == NULL){
+	    clicon_err(OE_YANG, errno, "Extension %s:%s not found", prefix, name);
+	    goto done;
+	}
+	if ((ys->ys_cv = cv_new(CGV_STRING)) == NULL){
+	    clicon_err(OE_YANG, errno, "%s: cv_new", __FUNCTION__); 
+	    goto done;
+	}
+	if ((cvret = cv_parse1(extra, ys->ys_cv, &reason)) < 0){ /* error */
+	    clicon_err(OE_YANG, errno, "parsing cv");
+	    goto done;
+	}
+	if (cvret == 0){ /* parsing failed */
+	    clicon_err(OE_YANG, errno, "Parsing CV: %s", reason);
+	    goto done;
+	}
+	free(extra);
+	break;
     default:
 	break;
     }
+    ok:
     retval = 0;
   done:
+    if (prefix)
+	free(prefix);
     return retval;
 }
 
diff --git a/lib/src/clixon_yang_parse.l b/lib/src/clixon_yang_parse.l
index eb235115..8c80af65 100644
--- a/lib/src/clixon_yang_parse.l
+++ b/lib/src/clixon_yang_parse.l
@@ -101,12 +101,13 @@ clixon_yang_parsewrap(void)
 %s ESCAPE
 %s COMMENT1
 %s COMMENT2
+%s UNKNOWN
 
 %%
  /* Common tokens */
 <KEYWORD,ARGUMENT,STRING0>[ \t]            
-<KEYWORD,ARGUMENT,STRING0><<EOF>> { return MY_EOF; }
-<KEYWORD,ARGUMENT,STRING0,COMMENT1>\n   { _YY->yy_linenum++; }
+<KEYWORD,ARGUMENT,STRING0,UNKNOWN><<EOF>> { return MY_EOF; }
+<KEYWORD,ARGUMENT,STRING0,COMMENT1,UNKNOWN>\n   { _YY->yy_linenum++; }
 <KEYWORD,ARGUMENT,STRING0>"/*"    { _YY->yy_lex_state = YYSTATE; BEGIN(COMMENT1); }
 <KEYWORD,ARGUMENT,STRING0>"//"    { _YY->yy_lex_state = YYSTATE; BEGIN(COMMENT2); }
 
@@ -182,7 +183,14 @@ clixon_yang_parsewrap(void)
 <KEYWORD>:                { return *yytext; }
 <KEYWORD>;                { return *yytext; }
 <KEYWORD>.                { clixon_yang_parselval.string = strdup(yytext);
-                             return CHAR;}
+                             BEGIN(UNKNOWN); return CHAR; }
+
+<UNKNOWN>:                { return *yytext; }
+<UNKNOWN>;                { BEGIN(KEYWORD); return *yytext; }
+<UNKNOWN>[ \t]            { return ' '; }
+<UNKNOWN>.                { clixon_yang_parselval.string = strdup(yytext);
+                            return CHAR; }
+
 
 
 <ARGUMENT>;                { BEGIN(KEYWORD); return *yytext; }
diff --git a/lib/src/clixon_yang_parse.y b/lib/src/clixon_yang_parse.y
index 68748c8a..b27f63ea 100644
--- a/lib/src/clixon_yang_parse.y
+++ b/lib/src/clixon_yang_parse.y
@@ -46,7 +46,6 @@
 
 %token MY_EOF 
 %token DQ           /* Double quote: " */
-%token K_UNKNOWN    /* template for error */
 %token <string> CHAR
 
 %type <string>    ustring
@@ -239,12 +238,18 @@ ystack_push(struct clicon_yang_yacc_arg *yy,
 
 /*! Add a yang statement to existing top-of-stack.
  *
- * Note: consumes 'argument' which assumes it is malloced and not freed by caller
+ * @param[in]  yy        Yang yacc argument
+ * @param[in]  keyword   Yang keyword
+ * @param[in]  argument  Yang argument
+ * @param[in]  extra     Yang extra for cornercases (unknown/extension)
+
+ * @note consumes 'argument' and 'extra' which assumes it is malloced and not freed by caller
  */
 static yang_stmt *
 ysp_add(struct clicon_yang_yacc_arg *yy, 
 	enum rfc_6020                keyword, 
-	char                        *argument)
+	char                        *argument,
+    	char                        *extra)
 {
     struct ys_stack *ystack = yy->yy_stack;
     yang_stmt       *ys = NULL;
@@ -262,7 +267,7 @@ ysp_add(struct clicon_yang_yacc_arg *yy,
     ys->ys_argument = argument;
     if (yn_insert(yn, ys) < 0) /* Insert into hierarchy */
 	goto err; 
-    if (ys_parse_sub(ys) < 0)     /* Check statement-specific syntax */
+    if (ys_parse_sub(ys, extra) < 0)     /* Check statement-specific syntax */
 	goto err2; /* dont free since part of tree */
 //  done:
     return ys;
@@ -276,12 +281,12 @@ ysp_add(struct clicon_yang_yacc_arg *yy,
 /*! combination of ysp_add and ysp_push for sub-modules */
 static yang_stmt *
 ysp_add_push(struct clicon_yang_yacc_arg *yy,
-	     int                          keyword,
+	     enum rfc_6020                keyword, 
 	     char                        *argument)
 {
     yang_stmt *ys;
 
-    if ((ys = ysp_add(yy, keyword, argument)) == NULL)
+    if ((ys = ysp_add(yy, keyword, argument, NULL)) == NULL)
 	return NULL;
     if (ystack_push(yy, (yang_node*)ys) == NULL)
 	return NULL;
@@ -330,12 +335,22 @@ file          : module_stmt MY_EOF
                        { clicon_debug(2,"file->submodule-stmt"); YYACCEPT; } 
               ;
 
-unknown_stmt  : K_UNKNOWN      { clixon_yang_parseerror(_yy, "unknown statement");clicon_debug(2,"unknown-stmt"); _YYERROR("0"); } 
-              ;
+  /* For extensions */
+unknown_stmt  : ustring  ':' ustring ';'
+               { char *id; if ((id=prefix_id_join($1, $3)) == NULL) _YYERROR("0");
+		   if (ysp_add(_yy, Y_UNKNOWN, id, NULL) == NULL) _YYERROR("0"); 
+		   clicon_debug(2,"unknown-stmt -> ustring : ustring");
+	       }
+              | ustring  ':' ustring ' ' string ';'
+               { char *id; if ((id=prefix_id_join($1, $3)) == NULL) _YYERROR("0");
+		   if (ysp_add(_yy, Y_UNKNOWN, id, $5) == NULL) _YYERROR("0"); 
+		   clicon_debug(2,"unknown-stmt -> ustring : ustring string");
+	       }
+	      ;
 
 /* module */
 module_stmt   : K_MODULE id_arg_str 
-                        { if ((_YY->yy_module = ysp_add_push(_yy, Y_MODULE, $2)) == NULL) _YYERROR("1");
+                  { if ((_YY->yy_module = ysp_add_push(_yy, Y_MODULE, $2)) == NULL) _YYERROR("1");
                         } 
                 '{' module_substmts '}' 
                         { if (ystack_pop(_yy) < 0) _YYERROR("2");
@@ -359,7 +374,7 @@ module_substmt : module_header_stmts { clicon_debug(2,"module-substmt -> module-
 
 /* submodule */
 submodule_stmt : K_SUBMODULE id_arg_str '{' submodule_substmts '}' 
-                      { if ((_YY->yy_module = ysp_add_push(_yy, Y_SUBMODULE, $2)) == NULL) _YYERROR("3"); 
+		{ if ((_YY->yy_module = ysp_add_push(_yy, Y_SUBMODULE, $2)) == NULL) _YYERROR("3"); 
                         clicon_debug(2,"submodule -> id-arg-str { submodule-stmts }"); 
                       }
               ;
@@ -422,7 +437,7 @@ revision_stmts : revision_stmts revision_stmt
               ;
 
 revision_stmt : K_REVISION string ';'  /* XXX date-arg-str */
-                     { if (ysp_add(_yy, Y_REVISION, $2) == NULL) _YYERROR("4"); 
+		{ if (ysp_add(_yy, Y_REVISION, $2, NULL) == NULL) _YYERROR("4"); 
 			 clicon_debug(2,"revision-stmt -> date-arg-str ;"); }
               | K_REVISION string 
                      { if (ysp_add_push(_yy, Y_REVISION, $2) == NULL) _YYERROR("5"); }
@@ -482,7 +497,7 @@ data_def_stmt : container_stmt       { clicon_debug(2,"data-def-stmt -> containe
 
 /* container */
 container_stmt : K_CONTAINER id_arg_str ';'
-                           { if (ysp_add(_yy, Y_CONTAINER, $2) == NULL) _YYERROR("7"); 
+		{ if (ysp_add(_yy, Y_CONTAINER, $2, NULL) == NULL) _YYERROR("7"); 
                              clicon_debug(2,"container-stmt -> CONTAINER id-arg-str ;");}
               | K_CONTAINER id_arg_str 
                           { if (ysp_add_push(_yy, Y_CONTAINER, $2) == NULL) _YYERROR("8"); }
@@ -512,7 +527,7 @@ container_substmt : when_stmt       { clicon_debug(2,"container-substmt -> when-
 
 /* leaf */
 leaf_stmt     : K_LEAF id_arg_str ';'
-                         { if (ysp_add(_yy, Y_LEAF, $2) == NULL) _YYERROR("10"); 
+		{ if (ysp_add(_yy, Y_LEAF, $2, NULL) == NULL) _YYERROR("10"); 
 			   clicon_debug(2,"leaf-stmt -> LEAF id-arg-str ;");}
               | K_LEAF id_arg_str 
                           { if (ysp_add_push(_yy, Y_LEAF, $2) == NULL) _YYERROR("11"); }
@@ -542,7 +557,7 @@ leaf_substmt  : when_stmt            { clicon_debug(2,"leaf-substmt -> when-stmt
 
 /* leaf-list */
 leaf_list_stmt : K_LEAF_LIST id_arg_str ';'
-                         { if (ysp_add(_yy, Y_LEAF_LIST, $2) == NULL) _YYERROR("13"); 
+		{ if (ysp_add(_yy, Y_LEAF_LIST, $2, NULL) == NULL) _YYERROR("13"); 
 			   clicon_debug(2,"leaf-list-stmt -> LEAF id-arg-str ;");}
               | K_LEAF_LIST id_arg_str 
                           { if (ysp_add_push(_yy, Y_LEAF_LIST, $2) == NULL) _YYERROR("14"); }
@@ -573,7 +588,7 @@ leaf_list_substmt : when_stmt        { clicon_debug(2,"leaf-list-substmt -> when
 
 /* list */
 list_stmt     : K_LIST id_arg_str ';' 
-                         { if (ysp_add(_yy, Y_LIST, $2) == NULL) _YYERROR("16"); 
+		{ if (ysp_add(_yy, Y_LIST, $2, NULL) == NULL) _YYERROR("16"); 
 			   clicon_debug(2,"list-stmt -> LIST id-arg-str ;"); }
               | K_LIST id_arg_str 
                           { if (ysp_add_push(_yy, Y_LIST, $2) == NULL) _YYERROR("17"); }
@@ -609,7 +624,7 @@ list_substmt  : when_stmt            { clicon_debug(2,"list-substmt -> when-stmt
 
 /* choice */
 choice_stmt   : K_CHOICE id_arg_str ';' 
-                         { if (ysp_add(_yy, Y_CHOICE, $2) == NULL) _YYERROR("19"); 
+	       { if (ysp_add(_yy, Y_CHOICE, $2, NULL) == NULL) _YYERROR("19"); 
 			   clicon_debug(2,"choice-stmt -> CHOICE id-arg-str ;"); }
               | K_CHOICE id_arg_str 
                           { if (ysp_add_push(_yy, Y_CHOICE, $2) == NULL) _YYERROR("20"); }
@@ -648,7 +663,7 @@ short_case_stmt : container_stmt   { clicon_debug(2,"short-case-substmt -> conta
 
 /* case */
 case_stmt   : K_CASE id_arg_str ';' 
-                         { if (ysp_add(_yy, Y_CASE, $2) == NULL) _YYERROR("22"); 
+	       { if (ysp_add(_yy, Y_CASE, $2, NULL) == NULL) _YYERROR("22"); 
 			   clicon_debug(2,"case-stmt -> CASE id-arg-str ;"); }
               | K_CASE id_arg_str 
                           { if (ysp_add_push(_yy, Y_CASE, $2) == NULL) _YYERROR("23"); }
@@ -676,7 +691,7 @@ case_substmt  : when_stmt            { clicon_debug(2,"case-substmt -> when-stmt
 
 /* anyxml */
 anyxml_stmt   : K_ANYXML  id_arg_str ';' 
-                         { if (ysp_add(_yy, Y_ANYXML, $2) == NULL) _YYERROR("25"); 
+	       { if (ysp_add(_yy, Y_ANYXML, $2, NULL) == NULL) _YYERROR("25"); 
 			   clicon_debug(2,"anyxml-stmt -> ANYXML id-arg-str ;"); }
               | K_ANYXML id_arg_str
                           { if (ysp_add_push(_yy, Y_ANYXML, $2) == NULL) _YYERROR("26"); }
@@ -704,7 +719,7 @@ anyxml_substmt  : when_stmt          { clicon_debug(2,"anyxml-substmt -> when-st
 
 /* uses */
 uses_stmt     : K_USES identifier_ref_arg_str ';' 
-                         { if (ysp_add(_yy, Y_USES, $2) == NULL) _YYERROR("28"); 
+	       { if (ysp_add(_yy, Y_USES, $2, NULL) == NULL) _YYERROR("28"); 
 			   clicon_debug(2,"uses-stmt -> USES id-arg-str ;"); }
               | K_USES identifier_ref_arg_str
                           { if (ysp_add_push(_yy, Y_USES, $2) == NULL) _YYERROR("29"); }
@@ -732,7 +747,7 @@ uses_substmt  : when_stmt            { clicon_debug(2,"uses-substmt -> when-stmt
 
 /* refine XXX need further refining */
 refine_stmt   : K_REFINE id_arg_str ';' 
-                         { if (ysp_add(_yy, Y_REFINE, $2) == NULL) _YYERROR("31"); 
+	       { if (ysp_add(_yy, Y_REFINE, $2, NULL) == NULL) _YYERROR("31"); 
 			   clicon_debug(2,"refine-stmt -> REFINE id-arg-str ;"); }
               | K_REFINE id_arg_str 
                           { if (ysp_add_push(_yy, Y_REFINE, $2) == NULL) _YYERROR("32"); }
@@ -782,7 +797,7 @@ augment_substmt : when_stmt          { clicon_debug(2,"augment-substmt -> when-s
 
 /* when */
 when_stmt   : K_WHEN string ';' 
-                         { if (ysp_add(_yy, Y_WHEN, $2) == NULL) _YYERROR("36"); 
+	       { if (ysp_add(_yy, Y_WHEN, $2, NULL) == NULL) _YYERROR("36"); 
 			   clicon_debug(2,"when-stmt -> WHEN string ;"); }
               | K_WHEN string
                           { if (ysp_add_push(_yy, Y_WHEN, $2) == NULL) _YYERROR("37"); }
@@ -804,7 +819,7 @@ when_substmt  : description_stmt { clicon_debug(2,"when-substmt -> description-s
 
 /* rpc */
 rpc_stmt   : K_RPC id_arg_str ';' 
-                         { if (ysp_add(_yy, Y_RPC, $2) == NULL) _YYERROR("39"); 
+	       { if (ysp_add(_yy, Y_RPC, $2, NULL) == NULL) _YYERROR("39"); 
 			   clicon_debug(2,"rpc-stmt -> RPC id-arg-str ;"); }
               | K_RPC id_arg_str
                           { if (ysp_add_push(_yy, Y_RPC, $2) == NULL) _YYERROR("40"); }
@@ -885,7 +900,7 @@ typedef_substmt : type_stmt          { clicon_debug(2,"typedef-substmt -> type-s
 
 /* Type */
 type_stmt     : K_TYPE identifier_ref_arg_str ';' 
-                         { if (ysp_add(_yy, Y_TYPE, $2) == NULL) _YYERROR("48"); 
+	       { if (ysp_add(_yy, Y_TYPE, $2, NULL) == NULL) _YYERROR("48"); 
 			   clicon_debug(2,"type-stmt -> TYPE identifier-ref-arg-str ;");}
               | K_TYPE identifier_ref_arg_str 
                          { if (ysp_add_push(_yy, Y_TYPE, $2) == NULL) _YYERROR("49"); 
@@ -953,7 +968,7 @@ grouping_substmt : status_stmt          { clicon_debug(2,"grouping-substmt -> st
 
 /* length-stmt */
 length_stmt   : K_LENGTH string ';' /* XXX length-arg-str */
-                         { if (ysp_add(_yy, Y_LENGTH, $2) == NULL) _YYERROR("53"); 
+	       { if (ysp_add(_yy, Y_LENGTH, $2, NULL) == NULL) _YYERROR("53"); 
 			   clicon_debug(2,"length-stmt -> LENGTH string ;"); }
 
               | K_LENGTH string
@@ -978,7 +993,7 @@ length_substmt : error_message_stmt  { clicon_debug(2,"length-substmt -> error-m
 
 /* Pattern */
 pattern_stmt  : K_PATTERN string ';' 
-                         { if (ysp_add(_yy, Y_PATTERN, $2) == NULL) _YYERROR("56"); 
+	       { if (ysp_add(_yy, Y_PATTERN, $2, NULL) == NULL) _YYERROR("56"); 
 			   clicon_debug(2,"pattern-stmt -> PATTERN string ;"); }
 
               | K_PATTERN string
@@ -1002,7 +1017,7 @@ pattern_substmt : reference_stmt     { clicon_debug(2,"pattern-substmt -> refere
 
 /* Extension */
 extension_stmt: K_EXTENSION id_arg_str ';' 
-                  { if (ysp_add(_yy, Y_EXTENSION, $2) == NULL) _YYERROR("59");
+	       { if (ysp_add(_yy, Y_EXTENSION, $2, NULL) == NULL) _YYERROR("59");
                     clicon_debug(2,"extenstion-stmt -> EXTENSION id-arg-str ;"); }
               | K_EXTENSION id_arg_str 
  	          { if (ysp_add_push(_yy, Y_EXTENSION, $2) == NULL) _YYERROR("60"); }
@@ -1033,7 +1048,7 @@ argument_stmt  : K_ARGUMENT id_arg_str ';'
 
 /* Feature */
 feature_stmt  : K_FEATURE id_arg_str ';' 
-                  { if (ysp_add(_yy, Y_FEATURE, $2) == NULL) _YYERROR("62");
+	       { if (ysp_add(_yy, Y_FEATURE, $2, NULL) == NULL) _YYERROR("62");
 		      clicon_debug(2,"feature-stmt -> FEATURE id-arg-str ;"); }
               | K_FEATURE id_arg_str
                   { if (ysp_add_push(_yy, Y_FEATURE, $2) == NULL) _YYERROR("63"); }
@@ -1059,7 +1074,7 @@ feature_substmt : if_feature_stmt    { clicon_debug(2,"feature-substmt -> if-fea
 
 /* Identity */
 identity_stmt  : K_IDENTITY string ';' /* XXX identifier-arg-str */
-                         { if (ysp_add(_yy, Y_IDENTITY, $2) == NULL) _YYERROR("65"); 
+	      { if (ysp_add(_yy, Y_IDENTITY, $2, NULL) == NULL) _YYERROR("65"); 
 			   clicon_debug(2,"identity-stmt -> IDENTITY string ;"); }
 
               | K_IDENTITY string
@@ -1085,7 +1100,7 @@ identity_substmt : base_stmt         { clicon_debug(2,"identity-substmt -> base-
 
 /* range-stmt */
 range_stmt   : K_RANGE string ';' /* XXX range-arg-str */
-                         { if (ysp_add(_yy, Y_RANGE, $2) == NULL) _YYERROR("68"); 
+	       { if (ysp_add(_yy, Y_RANGE, $2, NULL) == NULL) _YYERROR("68"); 
 			   clicon_debug(2,"range-stmt -> RANGE string ;"); }
 
               | K_RANGE string
@@ -1110,7 +1125,7 @@ range_substmt : error_message_stmt   { clicon_debug(2,"range-substmt -> error-me
 
 /* enum-stmt */
 enum_stmt     : K_ENUM string ';'
-                         { if (ysp_add(_yy, Y_ENUM, $2) == NULL) _YYERROR("71"); 
+	       { if (ysp_add(_yy, Y_ENUM, $2, NULL) == NULL) _YYERROR("71"); 
 			   clicon_debug(2,"enum-stmt -> ENUM string ;"); }
               | K_ENUM string
                          { if (ysp_add_push(_yy, Y_ENUM, $2) == NULL) _YYERROR("72"); }
@@ -1135,7 +1150,7 @@ enum_substmt  : value_stmt           { clicon_debug(2,"enum-substmt -> value-stm
 
 /* bit-stmt */
 bit_stmt     : K_BIT string ';'
-                         { if (ysp_add(_yy, Y_BIT, $2) == NULL) _YYERROR("74"); 
+	       { if (ysp_add(_yy, Y_BIT, $2, NULL) == NULL) _YYERROR("74"); 
 			   clicon_debug(2,"bit-stmt -> BIT string ;"); }
               | K_BIT string
                          { if (ysp_add_push(_yy, Y_BIT, $2) == NULL) _YYERROR("75"); }
@@ -1159,7 +1174,7 @@ bit_substmt   : position_stmt        { clicon_debug(2,"bit-substmt -> positition
 
 /* mus-stmt */
 must_stmt     : K_MUST string ';'
-                         { if (ysp_add(_yy, Y_MUST, $2) == NULL) _YYERROR("77"); 
+	       { if (ysp_add(_yy, Y_MUST, $2, NULL) == NULL) _YYERROR("77"); 
 			   clicon_debug(2,"must-stmt -> MUST string ;"); }
 
               | K_MUST string
@@ -1183,7 +1198,7 @@ must_substmt  : error_message_stmt   { clicon_debug(2,"must-substmt -> error-mes
 
 /* error-message-stmt */
 error_message_stmt   : K_ERROR_MESSAGE string ';'
-                          { if (ysp_add(_yy, Y_ERROR_MESSAGE, $2) == NULL) _YYERROR("80"); }
+	       { if (ysp_add(_yy, Y_ERROR_MESSAGE, $2, NULL) == NULL) _YYERROR("80"); }
 
 /* import */
 import_stmt   : K_IMPORT id_arg_str 
@@ -1206,144 +1221,144 @@ import_substmt : prefix_stmt {  clicon_debug(2,"import-stmt -> prefix-stmt"); }
 
 /* Simple statements */
 yang_version_stmt  : K_YANG_VERSION string ';' /* XXX yang-version-arg-str */
-                          { if (ysp_add(_yy, Y_YANG_VERSION, $2) == NULL) _YYERROR("83");
+		{ if (ysp_add(_yy, Y_YANG_VERSION, $2, NULL) == NULL) _YYERROR("83");
                             clicon_debug(2,"yang-version-stmt -> YANG-VERSION string"); }
               ;
 
 fraction_digits_stmt : K_FRACTION_DIGITS string ';' /* XXX: fraction-digits-arg-str */
-                          { if (ysp_add(_yy, Y_FRACTION_DIGITS, $2) == NULL) _YYERROR("84"); 
+		{ if (ysp_add(_yy, Y_FRACTION_DIGITS, $2, NULL) == NULL) _YYERROR("84"); 
                             clicon_debug(2,"fraction-digits-stmt -> FRACTION-DIGITS string"); }
               ;
 
 if_feature_stmt : K_IF_FEATURE identifier_ref_arg_str ';' 
-                          { if (ysp_add(_yy, Y_IF_FEATURE, $2) == NULL) _YYERROR("85"); 
+		{ if (ysp_add(_yy, Y_IF_FEATURE, $2, NULL) == NULL) _YYERROR("85"); 
                             clicon_debug(2,"if-feature-stmt -> IF-FEATURE identifier-ref-arg-str"); }
               ;
 
 value_stmt   : K_VALUE integer_value ';' 
-                          { if (ysp_add(_yy, Y_VALUE, $2) == NULL) _YYERROR("86"); 
+		{ if (ysp_add(_yy, Y_VALUE, $2, NULL) == NULL) _YYERROR("86"); 
                             clicon_debug(2,"value-stmt -> VALUE integer-value"); }
               ;
 
 position_stmt : K_POSITION integer_value ';' 
-                          { if (ysp_add(_yy, Y_POSITION, $2) == NULL) _YYERROR("87"); 
+		{ if (ysp_add(_yy, Y_POSITION, $2, NULL) == NULL) _YYERROR("87"); 
                             clicon_debug(2,"position-stmt -> POSITION integer-value"); }
               ;
 
 status_stmt   : K_STATUS string ';' /* XXX: status-arg-str */
-                          { if (ysp_add(_yy, Y_STATUS, $2) == NULL) _YYERROR("88"); 
+		{ if (ysp_add(_yy, Y_STATUS, $2, NULL) == NULL) _YYERROR("88"); 
                             clicon_debug(2,"status-stmt -> STATUS string"); }
               ;
 
 config_stmt   : K_CONFIG config_arg_str ';' 
-                          { if (ysp_add(_yy, Y_CONFIG, $2) == NULL) _YYERROR("89"); 
+		{ if (ysp_add(_yy, Y_CONFIG, $2, NULL) == NULL) _YYERROR("89"); 
                             clicon_debug(2,"config-stmt -> CONFIG config-arg-str"); }
               ;
 
 
 base_stmt     : K_BASE identifier_ref_arg_str ';' 
-                          { if (ysp_add(_yy, Y_BASE, $2)== NULL) _YYERROR("90"); 
+		{ if (ysp_add(_yy, Y_BASE, $2, NULL)== NULL) _YYERROR("90"); 
                             clicon_debug(2,"base-stmt -> BASE identifier-ref-arg-str"); }
               ;
 
 path_stmt     : K_PATH string ';' /* XXX: path-arg-str */
-                          { if (ysp_add(_yy, Y_PATH, $2)== NULL) _YYERROR("91"); 
+		{ if (ysp_add(_yy, Y_PATH, $2, NULL)== NULL) _YYERROR("91"); 
                             clicon_debug(2,"path-stmt -> PATH string"); }
               ;
 
 require_instance_stmt : K_REQUIRE_INSTANCE string ';' /* XXX: require-instance-arg-str */
-                          { if (ysp_add(_yy, Y_REQUIRE_INSTANCE, $2)== NULL) _YYERROR("92"); 
+		{ if (ysp_add(_yy, Y_REQUIRE_INSTANCE, $2, NULL)== NULL) _YYERROR("92"); 
                             clicon_debug(2,"require-instance-stmt -> REQUIRE-INSTANCE string"); }
               ;
 
 units_stmt    : K_UNITS string ';'
-                          { if (ysp_add(_yy, Y_UNITS, $2)== NULL) _YYERROR("93"); 
+		{ if (ysp_add(_yy, Y_UNITS, $2, NULL)== NULL) _YYERROR("93"); 
                             clicon_debug(2,"units-stmt -> UNITS string"); }
               ;
 
 default_stmt  : K_DEFAULT string ';'
-                          { if (ysp_add(_yy, Y_DEFAULT, $2)== NULL) _YYERROR("94"); 
+		{ if (ysp_add(_yy, Y_DEFAULT, $2, NULL)== NULL) _YYERROR("94"); 
                             clicon_debug(2,"default-stmt -> DEFAULT string"); }
               ;
 
 contact_stmt  : K_CONTACT string ';'
-                          { if (ysp_add(_yy, Y_CONTACT, $2)== NULL) _YYERROR("95"); 
+		{ if (ysp_add(_yy, Y_CONTACT, $2, NULL)== NULL) _YYERROR("95"); 
                             clicon_debug(2,"contact-stmt -> CONTACT string"); }
               ;
 
 revision_date_stmt : K_REVISION_DATE string ';'  /* XXX date-arg-str */
-                     { if (ysp_add(_yy, Y_REVISION_DATE, $2) == NULL) _YYERROR("96"); 
+		{ if (ysp_add(_yy, Y_REVISION_DATE, $2, NULL) == NULL) _YYERROR("96"); 
 			 clicon_debug(2,"revision-date-stmt -> date;"); }
               ;
 
 include_stmt  : K_INCLUDE id_arg_str ';'
-                         { if (ysp_add(_yy, Y_INCLUDE, $2)== NULL) _YYERROR("97"); 
+		{ if (ysp_add(_yy, Y_INCLUDE, $2, NULL)== NULL) _YYERROR("97"); 
                            clicon_debug(2,"include-stmt -> id-arg-str"); }
               | K_INCLUDE id_arg_str '{' revision_date_stmt '}'
-                         { if (ysp_add(_yy, Y_INCLUDE, $2)== NULL) _YYERROR("98"); 
+		{ if (ysp_add(_yy, Y_INCLUDE, $2, NULL)== NULL) _YYERROR("98"); 
                            clicon_debug(2,"include-stmt -> id-arg-str { revision-date-stmt }"); }
               ;
 
 namespace_stmt : K_NAMESPACE string ';'  /* XXX uri-str */
-                          { if (ysp_add(_yy, Y_NAMESPACE, $2)== NULL) _YYERROR("99"); 
+		{ if (ysp_add(_yy, Y_NAMESPACE, $2, NULL)== NULL) _YYERROR("99"); 
                             clicon_debug(2,"namespace-stmt -> NAMESPACE string"); }
               ;
 
 prefix_stmt   : K_PREFIX string ';' /* XXX prefix-arg-str */
-                          { if (ysp_add(_yy, Y_PREFIX, $2)== NULL) _YYERROR("100"); 
+		{ if (ysp_add(_yy, Y_PREFIX, $2, NULL)== NULL) _YYERROR("100"); 
 			     clicon_debug(2,"prefix-stmt -> PREFIX string ;");}
               ;
 
 description_stmt: K_DESCRIPTION string ';' 
-                         { if (ysp_add(_yy, Y_DESCRIPTION, $2)== NULL) _YYERROR("101"); 
+		{ if (ysp_add(_yy, Y_DESCRIPTION, $2, NULL)== NULL) _YYERROR("101"); 
 			   clicon_debug(2,"description-stmt -> DESCRIPTION string ;");}
               ;
 
 organization_stmt: K_ORGANIZATION string ';'
-                         { if (ysp_add(_yy, Y_ORGANIZATION, $2)== NULL) _YYERROR("102"); 
+		{ if (ysp_add(_yy, Y_ORGANIZATION, $2, NULL)== NULL) _YYERROR("102"); 
 			   clicon_debug(2,"organization-stmt -> ORGANIZATION string ;");}
               ;
 
 min_elements_stmt: K_MIN_ELEMENTS integer_value ';'
-                         { if (ysp_add(_yy, Y_MIN_ELEMENTS, $2)== NULL) _YYERROR("103"); 
+		{ if (ysp_add(_yy, Y_MIN_ELEMENTS, $2, NULL)== NULL) _YYERROR("103"); 
 			   clicon_debug(2,"min-elements-stmt -> MIN-ELEMENTS integer ;");}
               ;
 
 max_elements_stmt: K_MAX_ELEMENTS integer_value ';'
-                         { if (ysp_add(_yy, Y_MAX_ELEMENTS, $2)== NULL) _YYERROR("104"); 
+		{ if (ysp_add(_yy, Y_MAX_ELEMENTS, $2, NULL)== NULL) _YYERROR("104"); 
 			   clicon_debug(2,"max-elements-stmt -> MIN-ELEMENTS integer ;");}
               ;
 
 reference_stmt: K_REFERENCE string ';'
-                         { if (ysp_add(_yy, Y_REFERENCE, $2)== NULL) _YYERROR("105"); 
+		{ if (ysp_add(_yy, Y_REFERENCE, $2, NULL)== NULL) _YYERROR("105"); 
 			   clicon_debug(2,"reference-stmt -> REFERENCE string ;");}
               ;
 
 mandatory_stmt: K_MANDATORY string ';' 
                          { yang_stmt *ys;
-                           if ((ys = ysp_add(_yy, Y_MANDATORY, $2))== NULL) _YYERROR("106"); 
+			     if ((ys = ysp_add(_yy, Y_MANDATORY, $2, NULL))== NULL) _YYERROR("106"); 
 			   clicon_debug(2,"mandatory-stmt -> MANDATORY mandatory-arg-str ;");}
               ;
 
 presence_stmt: K_PRESENCE string ';' 
                          { yang_stmt *ys;
-                           if ((ys = ysp_add(_yy, Y_PRESENCE, $2))== NULL) _YYERROR("107"); 
+			     if ((ys = ysp_add(_yy, Y_PRESENCE, $2, NULL))== NULL) _YYERROR("107"); 
 			   clicon_debug(2,"presence-stmt -> PRESENCE string ;");}
               ;
 
 ordered_by_stmt: K_ORDERED_BY string ';' 
                          { yang_stmt *ys;
-                           if ((ys = ysp_add(_yy, Y_ORDERED_BY, $2))== NULL) _YYERROR("108"); 
+			     if ((ys = ysp_add(_yy, Y_ORDERED_BY, $2, NULL))== NULL) _YYERROR("108"); 
 			   clicon_debug(2,"ordered-by-stmt -> ORDERED-BY ordered-by-arg ;");}
               ;
 
 key_stmt      : K_KEY id_arg_str ';' /* XXX key_arg_str */
-                         { if (ysp_add(_yy, Y_KEY, $2)== NULL) _YYERROR("109"); 
+		{ if (ysp_add(_yy, Y_KEY, $2, NULL)== NULL) _YYERROR("109"); 
 			   clicon_debug(2,"key-stmt -> KEY id-arg-str ;");}
               ;
 
 unique_stmt   : K_UNIQUE id_arg_str ';' /* XXX key_arg_str */
-                         { if (ysp_add(_yy, Y_UNIQUE, $2)== NULL) _YYERROR("110"); 
+		{ if (ysp_add(_yy, Y_UNIQUE, $2, NULL)== NULL) _YYERROR("110"); 
 			   clicon_debug(2,"key-stmt -> KEY id-arg-str ;");}
               ;
 
diff --git a/lib/src/clixon_yang_type.c b/lib/src/clixon_yang_type.c
index 335e0ed6..2494cf5c 100644
--- a/lib/src/clixon_yang_type.c
+++ b/lib/src/clixon_yang_type.c
@@ -905,8 +905,8 @@ yang_type_resolve(yang_stmt   *ys,
     if (options)
 	*options = 0x0;
     *yrestype    = NULL; /* Initialization of resolved type that may not be necessary */
-    type      = ytype_id(ytype);     /* This is the type to resolve */
-    prefix    = ytype_prefix(ytype); /* And this its prefix */
+    type      = yarg_id(ytype);     /* This is the type to resolve */
+    prefix    = yarg_prefix(ytype); /* And this its prefix */
     /* Cache does not work for eg string length 32 */
     if (!yang_builtin(type) && ytype->ys_typecache != NULL){
 	if (yang_type_cache_get(ytype->ys_typecache, 
@@ -1034,7 +1034,7 @@ yang_type_get(yang_stmt    *ys,
 	goto done;
     }
     /* XXX: here we seem to have some problems if type is union */
-    type = ytype_id(ytype);
+    type = yarg_id(ytype);
     if (origtype)
 	*origtype = type;
     if (yang_type_resolve(ys, ytype, yrestype, 
diff --git a/test/test_restconf2.sh b/test/test_restconf2.sh
index f0ae519e..5e73ac31 100755
--- a/test/test_restconf2.sh
+++ b/test/test_restconf2.sh
@@ -13,11 +13,9 @@ cat <<EOF > $cfg
   <CLICON_CONFIGFILE>$cfg</CLICON_CONFIGFILE>
   <CLICON_YANG_DIR>/usr/local/var</CLICON_YANG_DIR>
   <CLICON_YANG_MODULE_MAIN>$fyang</CLICON_YANG_MODULE_MAIN>
-
   <CLICON_RESTCONF_PRETTY>false</CLICON_RESTCONF_PRETTY>
   <CLICON_SOCK>/usr/local/var/routing/routing.sock</CLICON_SOCK>
-  <CLICON_BACKEND_PIDFILE>/usr/local/var/routing/routing.pidfile</CLICON_BACKEND_PIDFILE>
-  <CLICON_CLI_GENMODEL_COMPLETION>1</CLICON_CLI_GENMODEL_COMPLETION>
+  <CLICON_BACKEND_PIDFILE>$dir/restconf.pidfile</CLICON_BACKEND_PIDFILE>
   <CLICON_XMLDB_DIR>/usr/local/var/routing</CLICON_XMLDB_DIR>
   <CLICON_XMLDB_PLUGIN>/usr/local/lib/xmldb/text.so</CLICON_XMLDB_PLUGIN>
 </config>
@@ -25,7 +23,7 @@ EOF
 
 cat <<EOF > $fyang
 module example{
-   container interfaces-config{
+   container cont1{
       list interface{
         key name;
         leaf name{
@@ -37,6 +35,11 @@ module example{
         }
       }
    }
+   container cont2{
+      leaf name{
+         type string;
+      }
+   }
 }
 EOF
 
@@ -62,56 +65,77 @@ sleep 1
 
 new "restconf tests"
 
+
 new "restconf POST initial tree"
-expectfn 'curl -s -X POST -d {"interfaces-config":{"interface":{"name":"local0","type":"regular"}}} http://localhost/restconf/data' ""
+expectfn 'curl -s -X POST -d {"cont1":{"interface":{"name":"local0","type":"regular"}}} http://localhost/restconf/data' ""
 
 new "restconf GET datastore"
-expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"interfaces-config": {"interface": \[{"name": "local0","type": "regular"}\]}}}'
+expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"cont1": {"interface": \[{"name": "local0","type": "regular"}\]}}}'
 
 new "restconf GET interface"
-expectfn "curl -s -X GET http://localhost/restconf/data/interfaces-config/interface=local0" '{"interface": \[{"name": "local0","type": "regular"}\]}'
+expectfn "curl -s -X GET http://localhost/restconf/data/cont1/interface=local0" '{"interface": \[{"name": "local0","type": "regular"}\]}'
 
 new "restconf GET if-type"
-expectfn "curl -s -X GET http://localhost/restconf/data/interfaces-config/interface=local0/type" '{"type": "regular"}'
+expectfn "curl -s -X GET http://localhost/restconf/data/cont1/interface=local0/type" '{"type": "regular"}'
 
 new "restconf POST interface"
-expectfn 'curl -s -X POST -d {"interface":{"name":"TEST","type":"eth0"}} http://localhost/restconf/data/interfaces-config' ""
+expectfn 'curl -s -X POST -d {"interface":{"name":"TEST","type":"eth0"}} http://localhost/restconf/data/cont1' ""
 
 new "restconf POST again"
-expectfn 'curl -s -X POST -d {"interface":{"name":"TEST","type":"eth0"}} http://localhost/restconf/data/interfaces-config' "Data resource already exis"
+expectfn 'curl -s -X POST -d {"interface":{"name":"TEST","type":"eth0"}} http://localhost/restconf/data/cont1' "Data resource already exis"
 
 new "restconf POST from top"
-expectfn 'curl -s -X POST -d {"interfaces-config":{"interface":{"name":"TEST","type":"eth0"}}} http://localhost/restconf/data' "Data resource already exists"
+expectfn 'curl -s -X POST -d {"cont1":{"interface":{"name":"TEST","type":"eth0"}}} http://localhost/restconf/data' "Data resource already exists"
 
 new "restconf DELETE"
-expectfn 'curl -s -X DELETE http://localhost/restconf/data/interfaces-config' ""
+expectfn 'curl -s -X DELETE http://localhost/restconf/data/cont1' ""
 
 new "restconf GET null datastore"
 expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": null}'
 
 new "restconf POST initial tree"
-expectfn 'curl -s -X POST -d {"interfaces-config":{"interface":{"name":"local0","type":"regular"}}} http://localhost/restconf/data' ""
+expectfn 'curl -s -X POST -d {"cont1":{"interface":{"name":"local0","type":"regular"}}} http://localhost/restconf/data' ""
+
+new "restconf GET initial tree"
+expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"cont1": {"interface": \[{"name": "local0","type": "regular"}\]}}}'
+
+new "restconf DELETE whole datastore"
+expectfn 'curl -s -X DELETE http://localhost/restconf/data' ""
+
+new "restconf GET null datastore"
+expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": null}'
 
 new "restconf PUT initial datastore" 
-expectfn 'curl -s -X PUT -d {"data":{"interfaces-config":{"interface":{"name":"local0","type":"regular"}}}} http://localhost/restconf/data' ""
+expectfn 'curl -s -X PUT -d {"data":{"cont1":{"interface":{"name":"local0","type":"regular"}}}} http://localhost/restconf/data' ""
 
 new "restconf GET datastore"
-expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"interfaces-config": {"interface": \[{"name": "local0","type": "regular"}\]}}}'
+expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"cont1": {"interface": \[{"name": "local0","type": "regular"}\]}}}'
+
+new "restconf PUT replace datastore" 
+expectfn 'curl -s -X PUT -d {"data":{"cont2":{"name":"foo"}}} http://localhost/restconf/data' ""
+
+new "restconf GET replaced datastore"
+expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"cont2": {"name": "foo"}}}'
+
+
+new "restconf PUT initial datastore again" 
+expectfn 'curl -s -X PUT -d {"data":{"cont1":{"interface":{"name":"local0","type":"regular"}}}} http://localhost/restconf/data' ""
 
 new "restconf PUT change interface"
-expectfn 'curl -s -X PUT -d {"interface":{"name":"local0","type":"atm0"}} http://localhost/restconf/data/interfaces-config/interface=local0' ""
+expectfn 'curl -s -X PUT -d {"interface":{"name":"local0","type":"atm0"}} http://localhost/restconf/data/cont1/interface=local0' ""
+
 
 new "restconf GET datastore atm"
-expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"interfaces-config": {"interface": \[{"name": "local0","type": "atm0"}\]}}}'
+expectfn "curl -s -X GET http://localhost/restconf/data" '{"data": {"cont1": {"interface": \[{"name": "local0","type": "atm0"}\]}}}'
 
 new "restconf PUT add interface"
-expectfn 'curl -s -X PUT -d {"interface":{"name":"TEST","type":"eth0"}} http://localhost/restconf/data/interfaces-config/interface=TEST' ""
+expectfn 'curl -s -X PUT -d {"interface":{"name":"TEST","type":"eth0"}} http://localhost/restconf/data/cont1/interface=TEST' ""
 
 new "restconf PUT change key error"
-expectfn 'curl -is -X PUT -d {"interface":{"name":"ALPHA","type":"eth0"}} http://localhost/restconf/data/interfaces-config/interface=TEST' "Bad request"
+expectfn 'curl -is -X PUT -d {"interface":{"name":"ALPHA","type":"eth0"}} http://localhost/restconf/data/cont1/interface=TEST' "Bad request"
 
 new "restconf POST invalid no type"
-expectfn 'curl -s -X POST -d {"interface":{"name":"ALPHA"}} http://localhost/restconf/data/interfaces-config' "Bad request"
+expectfn 'curl -s -X POST -d {"interface":{"name":"ALPHA"}} http://localhost/restconf/data/cont1' "Bad request"
 
 new "Kill restconf daemon"
 sudo pkill -u www-data clixon_restconf
diff --git a/test/test_yang.sh b/test/test_yang.sh
index 15eeba11..b53ad8d3 100755
--- a/test/test_yang.sh
+++ b/test/test_yang.sh
@@ -6,6 +6,7 @@
 
 cfg=$dir/conf_yang.xml
 fyang=$dir/test.yang
+fyangerr=$dir/err.yang
 
 cat <<EOF > $cfg
 <config>
@@ -25,6 +26,12 @@ EOF
 
 cat <<EOF > $fyang
 module example{
+   prefix ex;
+   extension c-define {
+      description "Example from RFC 6020";
+      argument "name";
+   }
+   ex:c-define "MY_INTERFACES";
    container x {
     list y {
       key "a b";
@@ -75,6 +82,17 @@ module example{
 }
 EOF
 
+# This yang definition uses an extension which is not defined. Error when loading
+cat <<EOF > $fyangerr
+module example{
+   prefix ex;
+   extension c-define {
+      description "Example from RFC 6020";
+      argument "name";
+   }
+   ex:not-defined ARGUMENT;
+}
+EOF
 # kill old backend (if any)
 new "kill old backend"
 sudo clixon_backend -zf $cfg -y $fyang
@@ -89,6 +107,13 @@ if [ $? -ne 0 ]; then
     err
 fi
 
+new "cli defined extension"
+expectfn "$clixon_cli -1f $cfg -y $fyang show version" "3."
+
+new "cli not defined extension"
+# This text yields an error, but the test cannot detect the error message yet
+#expectfn "$clixon_cli -1f $cfg -y $fyangerr show version" "Yang error: Extension ex:not-defined not found"
+
 new "netconf edit config"
 expecteof "$clixon_netconf -qf $cfg -y $fyang" "<rpc><edit-config><target><candidate/></target><config><x><y><a>1</a><b>2</b><c>5</c></y><d/></x></config></edit-config></rpc>]]>]]>" "^<rpc-reply><ok/></rpc-reply>]]>]]>$"
 
diff --git a/yang/ietf-netconf-acm@2012-02-22.yang b/yang/ietf-netconf-acm@2012-02-22.yang
index 99ad961f..32888d51 100644
--- a/yang/ietf-netconf-acm@2012-02-22.yang
+++ b/yang/ietf-netconf-acm@2012-02-22.yang
@@ -194,7 +194,7 @@ module ietf-netconf-acm {
      */
 
     container nacm {
-	/*	nacm:default-deny-all; XXX How is this parsed ?? */
+	nacm:default-deny-all;
 
 	description
 	    "Parameters for NETCONF Access Control Model.";