diff --git a/CHANGELOG.md b/CHANGELOG.md
index 11ffa9b7..f530b23c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,6 +35,15 @@
 * [3.3.2](#332) Aug 27 2017
 * [3.3.1](#331) June 7 2017
 
+## Refine branch
+
+* Break-out RFC 7950 Section 6.1 tokenization
+  * This enables full string lexical parsing of some rules previously not fully compliant, including:
+    * refine, uses-augment, augment, if-feature, type, base.
+  * Also solves previous tokenization issues
+    * [String concatenation in YANG model leads to syntax error ](https://github.com/clicon/clixon/issues/265)
+    * [Can't use + symbol in the enum statement without quotes](https://github.com/clicon/clixon/issues/241)
+
 ## 5.8.0
 Planned: July 2022
 
@@ -122,6 +131,8 @@ Developers may need to change their code
 
 ### Corrected Bugs
 
+* Fixed: [Can't use + symbol in the enum statement without quotes](https://github.com/clicon/clixon/issues/241)
+* Fixed: [String concatenation in YANG model leads to syntax error ](https://github.com/clicon/clixon/issues/265)
 * Fixed: ["autocli:hide-show" extension cause bug in xmldb_put method #343](https://github.com/clicon/clixon/issues/343)
 * Fixed: [Schema Ambiguity Error with openconfig-system re: NTP](https://github.com/clicon/clixon/issues/334)
 * Fixed: [YANG mandatory statements within case nodes do not work](https://github.com/clicon/clixon/issues/344)
diff --git a/lib/clixon/clixon_yang.h b/lib/clixon/clixon_yang.h
index c51cd979..281274d6 100644
--- a/lib/clixon/clixon_yang.h
+++ b/lib/clixon/clixon_yang.h
@@ -229,6 +229,7 @@ int       yang_stats(yang_stmt *y, uint64_t *nrp, size_t *szp);
 yang_stmt *yspec_new(void);
 yang_stmt *ys_new(enum rfc_6020 keyw);
 yang_stmt *ys_prune(yang_stmt *yp, int i);
+int        ys_prune_self(yang_stmt *ys);
 int        ys_free1(yang_stmt *ys, int self);
 int        ys_free(yang_stmt *ys);
 int        ys_cp(yang_stmt *nw, yang_stmt *old);
diff --git a/lib/clixon/clixon_yang_parse_lib.h b/lib/clixon/clixon_yang_parse_lib.h
index 1072229e..a2cc6a4c 100644
--- a/lib/clixon/clixon_yang_parse_lib.h
+++ b/lib/clixon/clixon_yang_parse_lib.h
@@ -59,6 +59,6 @@ int        yang_spec_parse_file(clicon_handle h, char *filename, yang_stmt *yspe
 int        yang_spec_load_dir(clicon_handle h, char *dir, yang_stmt *yspec);
 int        ys_parse_date_arg(char *datearg, uint32_t *dateint);
 cg_var    *ys_parse(yang_stmt *ys, enum cv_type cvtype);
-int        ys_parse_sub(yang_stmt *ys, char *extra);
+int        ys_parse_sub(yang_stmt *ys, const char *filename, char *extra);
 
 #endif  /* _CLIXON_YANG_LIB_H_ */
diff --git a/lib/src/Makefile.in b/lib/src/Makefile.in
index f300cf7b..66096ce9 100644
--- a/lib/src/Makefile.in
+++ b/lib/src/Makefile.in
@@ -77,7 +77,7 @@ SRC     = clixon_sig.c clixon_uid.c clixon_log.c clixon_err.c clixon_event.c \
 	  clixon_xml.c clixon_xml_io.c clixon_xml_sort.c clixon_xml_map.c clixon_xml_vec.c \
 	  clixon_xml_bind.c clixon_json.c clixon_proc.c \
 	  clixon_yang.c clixon_yang_type.c clixon_yang_module.c \
-	  clixon_yang_parse_lib.c clixon_yang_parse_sub.c \
+	  clixon_yang_parse_lib.c clixon_yang_sub_parse.c \
           clixon_yang_cardinality.c clixon_xml_changelog.c clixon_xml_nsctx.c \
 	  clixon_path.c clixon_validate.c \
 	  clixon_hash.c clixon_options.c clixon_data.c clixon_plugin.c \
@@ -95,7 +95,8 @@ YACCOBJS = lex.clixon_xml_parse.o clixon_xml_parse.tab.o \
             lex.clixon_api_path_parse.o clixon_api_path_parse.tab.o \
             lex.clixon_instance_id_parse.o clixon_instance_id_parse.tab.o \
             lex.clixon_text_syntax_parse.o clixon_text_syntax_parse.tab.o \
-            lex.clixon_if_feature_parse.o clixon_if_feature_parse.tab.o 
+            lex.clixon_yang_sub_parse.o clixon_yang_sub_parse.tab.o \
+            lex.clixon_yang_schemanode_parse.o clixon_yang_schemanode_parse.tab.o 
 
 # Generated src 
 GENSRC  = build.c 
@@ -120,14 +121,15 @@ endif
 
 clean:
 	rm -f $(OBJS) $(MYLIBLINK) $(MYLIBSTATIC) $(MYLIBDYNAMIC) $(GENOBJS) $(GENSRC) *.core
-	rm -f clixon_xml_parse.tab.[ch] clixon_xml_parse.yy.[co]
-	rm -f clixon_yang_parse.tab.[ch] clixon_yang_parse.[co]
-	rm -f clixon_json_parse.tab.[ch] clixon_json_parse.[co]
-	rm -f clixon_xpath_parse.tab.[ch] clixon_xpath_parse.[co]
-	rm -f clixon_api_path_parse.tab.[ch] clixon_api_path_parse.[co]
-	rm -f clixon_instance_id_parse.tab.[ch] clixon_instance_id_parse.[co]
-	rm -f clixon_text_syntax_parse.tab.[ch] clixon_text_syntax_parse.[co]
-	rm -f clixon_if_feature_parse.tab.[ch] clixon_if_feature_parse.[co]
+	rm -f clixon_xml_parse.tab.[ch] clixon_xml_parse.[o]
+	rm -f clixon_yang_parse.tab.[ch] clixon_yang_parse.[o]
+	rm -f clixon_json_parse.tab.[ch] clixon_json_parse.[o]
+	rm -f clixon_xpath_parse.tab.[ch] clixon_xpath_parse.[o]
+	rm -f clixon_api_path_parse.tab.[ch] clixon_api_path_parse.[o]
+	rm -f clixon_instance_id_parse.tab.[ch] clixon_instance_id_parse.[o]
+	rm -f clixon_text_syntax_parse.tab.[ch] clixon_text_syntax_parse.[o]
+	rm -f clixon_yang_sub_parse.tab.[ch] clixon_yang_sub_parse.[o]
+	rm -f clixon_yang_schemanode_parse.tab.[ch] clixon_yang_schemanode_parse.[o]
 	rm -f lex.clixon_xml_parse.c
 	rm -f lex.clixon_yang_parse.c
 	rm -f lex.clixon_json_parse.c
@@ -135,7 +137,7 @@ clean:
 	rm -f lex.clixon_api_path_parse.c
 	rm -f lex.clixon_instance_id_parse.c
 	rm -f lex.clixon_text_syntax_parse.c
-	rm -f lex.clixon_if_feature_parse.c
+	rm -f lex.clixon_yang_sub_parse.c
 	rm -f *.gcda *.gcno *.gcov # coverage
 
 #############################################################################
@@ -241,17 +243,30 @@ clixon_text_syntax_parse.tab.c:	clixon_text_syntax_parse.tab.h
 lex.clixon_text_syntax_parse.o : lex.clixon_text_syntax_parse.c clixon_text_syntax_parse.tab.h
 	$(CC) $(INCLUDES) $(CPPFLAGS) $(CFLAGS) -Wno-error -c $<
 
-# if-feature-expr parser
-lex.clixon_if_feature_parse.c : clixon_if_feature_parse.l clixon_if_feature_parse.tab.h
-	$(LEX) -Pclixon_if_feature_parse clixon_if_feature_parse.l # -d is debug
+# yang-sub parser
+lex.clixon_yang_sub_parse.c : clixon_yang_sub_parse.l clixon_yang_sub_parse.tab.h
+	$(LEX) -Pclixon_yang_sub_parse clixon_yang_sub_parse.l # -d is debug
 
-clixon_if_feature_parse.tab.h: clixon_if_feature_parse.y
-	$(YACC) -l -d -b clixon_if_feature_parse -p clixon_if_feature_parse clixon_if_feature_parse.y # -t is debug
+clixon_yang_sub_parse.tab.h: clixon_yang_sub_parse.y
+	$(YACC) -l -d -b clixon_yang_sub_parse -p clixon_yang_sub_parse clixon_yang_sub_parse.y # -t is debug
 
 # extra rule to avoid parallell yaccs
-clixon_if_feature_parse.tab.c:	clixon_if_feature_parse.tab.h
+clixon_yang_sub_parse.tab.c:	clixon_yang_sub_parse.tab.h
 
-lex.clixon_if_feature_parse.o : lex.clixon_if_feature_parse.c clixon_if_feature_parse.tab.h
+lex.clixon_yang_sub_parse.o : lex.clixon_yang_sub_parse.c clixon_yang_sub_parse.tab.h
+	$(CC) $(INCLUDES) $(CPPFLAGS) $(CFLAGS) -Wno-error -c $<
+
+# descendant-schema-nodeid parser
+lex.clixon_yang_schemanode_parse.c : clixon_yang_schemanode_parse.l clixon_yang_schemanode_parse.tab.h
+	$(LEX) -Pclixon_yang_schemanode_parse clixon_yang_schemanode_parse.l # -d is debug
+
+clixon_yang_schemanode_parse.tab.h: clixon_yang_schemanode_parse.y
+	$(YACC) -l -d -b clixon_yang_schemanode_parse -p clixon_yang_schemanode_parse clixon_yang_schemanode_parse.y # -t is debug
+
+# extra rule to avoid parallell yaccs
+clixon_yang_schemanode_parse.tab.c:	clixon_yang_schemanode_parse.tab.h
+
+lex.clixon_yang_schemanode_parse.o : lex.clixon_yang_schemanode_parse.c clixon_yang_schemanode_parse.tab.h
 	$(CC) $(INCLUDES) $(CPPFLAGS) $(CFLAGS) -Wno-error -c $<
 
 distclean: clean
diff --git a/lib/src/clixon_text_syntax_parse.l b/lib/src/clixon_text_syntax_parse.l
index 11c4f73b..70dd5ccf 100644
--- a/lib/src/clixon_text_syntax_parse.l
+++ b/lib/src/clixon_text_syntax_parse.l
@@ -94,7 +94,6 @@ int clixon_text_syntax_parsewrap(void)
 <INITIAL>[^\n\r \t\[\]\{\}\;\"]+  {
                             clixon_text_syntax_parselval.string = strdup(yytext);
                             return TOKEN; }
-<INITIAL>.                { return -1; }
 
 <COMMENT>\n               { _TS->ts_linenum++; BEGIN(_TS->ts_lex_state);}
 <COMMENT><<EOF>>          { return MY_EOF; }
@@ -106,7 +105,6 @@ int clixon_text_syntax_parsewrap(void)
 <STRING>\"                { BEGIN(_TS->ts_lex_state); return *yytext; }
 <STRING>[^\n\"]+          { clixon_text_syntax_parselval.string = strdup(yytext);
                             return TOKEN; }
-<STRING>.                 { return -1; }
 
 %%
 
diff --git a/lib/src/clixon_xml_nsctx.c b/lib/src/clixon_xml_nsctx.c
index 099272e9..22bb27be 100644
--- a/lib/src/clixon_xml_nsctx.c
+++ b/lib/src/clixon_xml_nsctx.c
@@ -95,7 +95,7 @@ xml_nsctx_namespace_netconf_default(clicon_handle h)
 
 /*! Create and initialize XML namespace context
  * @param[in] prefix    Namespace prefix, or NULL for default
- * @param[in] ns	    Set this namespace. If NULL create empty nsctx
+ * @param[in] ns        Set this namespace. If NULL create empty nsctx
  * @retval    nsc       Return namespace context in form of a cvec
  * @retval    NULL      Error
  * @code
diff --git a/lib/src/clixon_xml_parse.l b/lib/src/clixon_xml_parse.l
index a33c5c37..d6970e5e 100644
--- a/lib/src/clixon_xml_parse.l
+++ b/lib/src/clixon_xml_parse.l
@@ -139,7 +139,6 @@ ncname     {namestart}{namechar}*
 <STATEA>\r            { clixon_xml_parselval.string = "\n";return WHITESPACE; }
 <STATEA>\n            { clixon_xml_parselval.string = "\n"; _XY->xy_linenum++;return WHITESPACE; }
 <STATEA>[^&\r\n \t\<]+ { clixon_xml_parselval.string = yytext; return CHARDATA; /* Optimized */}
-<STATEA>.             { clixon_xml_parselval.string = yytext; return CHARDATA; }
 
 	/* @see xml_chardata_encode */
 <AMPERSAND>"amp;"    { BEGIN(_XY->xy_lex_state); clixon_xml_parselval.string = "&"; return CHARDATA;}
diff --git a/lib/src/clixon_yang.c b/lib/src/clixon_yang.c
index f99fc834..a1532442 100644
--- a/lib/src/clixon_yang.c
+++ b/lib/src/clixon_yang.c
@@ -80,7 +80,7 @@
 #include "clixon_data.h"
 #include "clixon_options.h"
 #include "clixon_yang_parse.h"
-#include "clixon_yang_parse_sub.h"
+#include "clixon_yang_sub_parse.h"
 #include "clixon_yang_parse_lib.h"
 #include "clixon_yang_cardinality.h"
 #include "clixon_yang_type.h"
@@ -673,6 +673,7 @@ ys_free1(yang_stmt *ys,
  * @retval     NULL No such node, nothing done
  * @retval     yc   returned orphaned yang node
  * @see ys_free Deallocate yang node
+ * @see ys_prune_self Prune child itself
  * @note Do not call this in a loop of yang children (unless you know what you are doing)
  */
 yang_stmt *
@@ -705,7 +706,7 @@ ys_prune(yang_stmt *yp,
  * @see ys_free Deallocate yang node
  * @note Do not call this in a loop of yang children (unless you know what you are doing)
  */
-static int
+int
 ys_prune_self(yang_stmt *ys)
 {
     int        retval = -1;
@@ -2800,6 +2801,8 @@ yang_features(clicon_handle h,
     int        i;
     int        j;
     yang_stmt *ys = NULL;
+    yang_stmt *ymod;
+    const char *mainfile = NULL;
     int        ret;
 
     i = 0;
@@ -2807,8 +2810,10 @@ yang_features(clicon_handle h,
 	ys = yt->ys_stmt[i];
 	if (ys->ys_keyword == Y_IF_FEATURE){
 	    /* Parse the if-feature-expr string using yang sub-parser */
+	    if ((ymod = ys_module(ys)) != NULL)
+		mainfile = yang_filename_get(ymod);
 	    ret = 0;
-	    if (yang_if_feature_parse(yang_argument_get(ys), ys, 1, &ret) < 0)
+	    if (yang_subparse(yang_argument_get(ys), ys, YA_IF_FEATURE, mainfile, 1, &ret) < 0)
 		goto done;
 	    clicon_debug(1, "%s %s %d", __FUNCTION__, yang_argument_get(ys), ret);
 	    if (ret == 0)
@@ -2938,6 +2943,7 @@ yang_datanode(yang_stmt *ys)
 /*! All the work for schema_nodeid functions both absolute and descendant
  *
  * @param[in]  yn    Yang node. For absolute schemanodeids this should be a module, otherwise any yang
+ * @param[in]  yspec Yang spec (Cornsercase if yn is pruned)
  * @param[in]  cvv   Schema-node path encoded as a name/value pair list.
  * @param[in]  nsc   Namespace context from yang for the prefixes (names) of cvv
  * @param[out] yres  Result yang statement node, or NULL if not found
@@ -2954,6 +2960,7 @@ yang_datanode(yang_stmt *ys)
  */
 static int
 schema_nodeid_iterate(yang_stmt    *yn,
+		      yang_stmt    *yspec,
 		      cvec         *nodeid_cvv,
 		      cvec         *nsc,
 		      yang_stmt   **yres)
@@ -2966,9 +2973,7 @@ schema_nodeid_iterate(yang_stmt    *yn,
     yang_stmt       *yp;
     cg_var          *cv;
     char            *ns;
-    yang_stmt       *yspec;
 
-    yspec = ys_spec(yn);
     yp = yn;
     /* Iterate over node identifiers /prefix:id/... */
     cv = NULL;    
@@ -3050,8 +3055,11 @@ yang_abs_schema_nodeid(yang_stmt    *yn,
     yang_stmt    *ymod;
     char         *str;
 
+    if ((yspec = ys_spec(yn)) == NULL){
+	clicon_err(OE_YANG, EINVAL, "No yang spec");
+	goto done;
+    }
     *yres = NULL;
-    yspec = ys_spec(yn);
     /* check absolute schema_nodeid */
     if (schema_nodeid[0] != '/'){
 	clicon_err(OE_YANG, EINVAL, "absolute schema nodeid should start with /");
@@ -3099,7 +3107,7 @@ yang_abs_schema_nodeid(yang_stmt    *yn,
 	goto done;
     }
     /* Iterate through cvv to find schemanode using ymod as starting point (since it is absolute) */
-    if (schema_nodeid_iterate(ymod, nodeid_cvv, nsc, yres) < 0)
+    if (schema_nodeid_iterate(ymod, yspec, nodeid_cvv, nsc, yres) < 0)
 	goto done;
  ok:
     retval = 0;
@@ -3112,9 +3120,10 @@ yang_abs_schema_nodeid(yang_stmt    *yn,
 }
 
 /*! Given a descendant schema-nodeid (eg a/b/c) find matching yang spec  
- * @param[in]  yn            Yang node
+ * @param[in]  yn            Yang node (must be part of yspec tree, cannot be "dangling")
  * @param[in]  schema_nodeid Descendant schema-node-id, ie a/b
  * @param[in]  keyword       A schemode of this type, or -1 if any
+ * @param[in]  ns            Namespace context
  * @param[out] yres          First yang node matching schema nodeid
  * @retval     0             OK
  * @retval    -1             Error, with clicon_err called
@@ -3130,12 +3139,17 @@ yang_desc_schema_nodeid(yang_stmt    *yn,
     cvec         *nodeid_cvv = NULL;
     cg_var       *cv;
     char         *str;
+    yang_stmt    *yspec;
     cvec         *nsc = NULL;
     
     if (schema_nodeid == NULL || strlen(schema_nodeid) == 0){
 	clicon_err(OE_YANG, EINVAL, "nodeid is empty");
 	goto done;
     }
+    if ((yspec = ys_spec(yn)) == NULL){
+	clicon_err(OE_YANG, EINVAL, "No yang spec");
+	goto done;
+    }
     *yres = NULL;
     /* check absolute schema_nodeid */
     if (schema_nodeid[0] == '/'){
@@ -3161,11 +3175,13 @@ yang_desc_schema_nodeid(yang_stmt    *yn,
 	    cv_name_set(cv, NULL);
 	}
     }
-    /* Make a namespace context from yang for the prefixes (names) of nodeid_cvv */
+    /* Make a namespace context from yang for the prefixes (names) of nodeid_cvv 
+     * Requires yn exist in hierarchy
+     */
     if (xml_nsctx_yang(yn, &nsc) < 0)
 	goto done;
     /* Iterate through cvv to find schemanode using yn as relative starting point */
-    if (schema_nodeid_iterate(yn, nodeid_cvv, nsc, yres) < 0)
+    if (schema_nodeid_iterate(yn, yspec, nodeid_cvv, nsc, yres) < 0)
 	goto done;
  ok:
     retval = 0;
diff --git a/lib/src/clixon_yang_parse.l b/lib/src/clixon_yang_parse.l
index 6ce16cf5..3e785020 100644
--- a/lib/src/clixon_yang_parse.l
+++ b/lib/src/clixon_yang_parse.l
@@ -119,7 +119,6 @@ identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
 <KEYWORD>anydata          { BEGIN(STRARG);  return K_ANYDATA; }
 <KEYWORD>anyxml           { BEGIN(STRARG);  return K_ANYXML; }
 <KEYWORD>argument         { BEGIN(STRARG);  return K_ARGUMENT; }
-<KEYWORD>base             { BEGIN(STRARG);  return K_BASE; }
 <KEYWORD>belongs-to       { BEGIN(STRARG);  return K_BELONGS_TO; }
 <KEYWORD>bit              { BEGIN(STRARG);  return K_BIT; }
 <KEYWORD>case             { BEGIN(STRARG);  return K_CASE; }
@@ -137,12 +136,9 @@ identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
 <KEYWORD>module           { BEGIN(STRARG);  return K_MODULE; }
 <KEYWORD>notification     { BEGIN(STRARG);  return K_NOTIFICATION; }
 <KEYWORD>prefix           { BEGIN(STRARG);  return K_PREFIX; }
-<KEYWORD>refine           { BEGIN(STRARG);  return K_REFINE; }
 <KEYWORD>rpc              { BEGIN(STRARG);  return K_RPC; }
 <KEYWORD>submodule        { BEGIN(STRARG);  return K_SUBMODULE; }
-<KEYWORD>type             { BEGIN(STRARG);  return K_TYPE; }
 <KEYWORD>typedef          { BEGIN(STRARG);  return K_TYPEDEF; }
-<KEYWORD>uses             { BEGIN(STRARG);  return K_USES; }
 
  /* RFC 7950 keywords using boolean string arguments */
 <KEYWORD>config           { BEGIN(BOOLEAN); return K_CONFIG; }
@@ -157,6 +153,7 @@ identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
 
  /* RFC 7950 keywords using strings  */
 <KEYWORD>augment          { BEGIN(STRING);  return K_AUGMENT; }
+<KEYWORD>base             { BEGIN(STRING);  return K_BASE; }
 <KEYWORD>contact          { BEGIN(STRING);  return K_CONTACT; }
 <KEYWORD>default          { BEGIN(STRING);  return K_DEFAULT; }
 <KEYWORD>description      { BEGIN(STRING);  return K_DESCRIPTION; }
@@ -178,13 +175,16 @@ identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
 <KEYWORD>path             { BEGIN(STRING);  return K_PATH; }
 <KEYWORD>pattern          { BEGIN(STRING);  return K_PATTERN; }
 <KEYWORD>presence         { BEGIN(STRING);  return K_PRESENCE; }
+<KEYWORD>type             { BEGIN(STRING);  return K_TYPE; }
 <KEYWORD>unique           { BEGIN(STRING);  return K_UNIQUE; }
 <KEYWORD>range            { BEGIN(STRING);  return K_RANGE; }
 <KEYWORD>reference        { BEGIN(STRING);  return K_REFERENCE; }
+<KEYWORD>refine           { BEGIN(STRING);  return K_REFINE; }
 <KEYWORD>revision         { BEGIN(STRING);  return K_REVISION; }
 <KEYWORD>revision-date    { BEGIN(STRING);  return K_REVISION_DATE; }
 <KEYWORD>status           { BEGIN(STRING);  return K_STATUS; }
 <KEYWORD>units            { BEGIN(STRING);  return K_UNITS; }
+<KEYWORD>uses             { BEGIN(STRING);  return K_USES; }
 <KEYWORD>when             { BEGIN(STRING);  return K_WHEN; }
 <KEYWORD>yang-version     { BEGIN(STRING);  return K_YANG_VERSION; }
 <KEYWORD>:                { return *yytext; }
@@ -239,7 +239,6 @@ identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
 <STRARG>;                  { BEGIN(KEYWORD); return *yytext; }
 <STRARG>{identifier}       { clixon_yang_parselval.string = strdup(yytext);
                              return IDENTIFIER;}
-
 <STRARG>.                  { return *yytext; }
 
 <STRING>\{                { BEGIN(KEYWORD); return *yytext; }
@@ -247,7 +246,7 @@ identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
 <STRING>\"                { _YY->yy_lex_string_state =STRING; BEGIN(STRINGDQ); return *yytext; }
 <STRING>\'                { _YY->yy_lex_string_state =STRING; BEGIN(STRINGSQ); return *yytext; }
 <STRING>\+                { return *yytext; }
-<STRING>[^\"\'\+\{\;\n \t\r]+    { clixon_yang_parselval.string = strdup(yytext); /* XXX [.]+ */
+<STRING>[^\"\'\{\;\n \t\r]+ { clixon_yang_parselval.string = strdup(yytext); /* XXX [.]+ */
                             return CHARS;}
 
 <STRINGDQ>\\              { _YY->yy_lex_state = STRINGDQ; BEGIN(DQESC); }
diff --git a/lib/src/clixon_yang_parse.y b/lib/src/clixon_yang_parse.y
index e778479e..a29e0536 100644
--- a/lib/src/clixon_yang_parse.y
+++ b/lib/src/clixon_yang_parse.y
@@ -68,15 +68,12 @@
 %type <string>    qstring
 %type <string>    string
 %type <string>    integer_value_str
-%type <string>    identifier_ref
+%type <string>    identifier_ref_arg_str
 %type <string>    if_feature_expr_str
-%type <string>    abs_schema_nodeid
-%type <string>    desc_schema_nodeid_strs
-%type <string>    desc_schema_nodeid_str
-%type <string>    desc_schema_nodeid
-%type <string>    node_identifier
+%type <string>    refine_arg_str
+%type <string>    augment_arg_str
+%type <string>    uses_augment_arg_str
 %type <string>    identifier_str
-%type <string>    identifier_ref_str
 %type <string>    bool_str
 
 /* rfc 6020 keywords 
@@ -293,7 +290,7 @@ ystack_push(clixon_yang_yacc *yy,
  * @note consumes 'argument' and 'extra' which assumes it is malloced and not freed by caller
  */
 static yang_stmt *
-ysp_add(clixon_yang_yacc *yy, 
+ysp_add(clixon_yang_yacc *yy,
 	enum rfc_6020     keyword, 
 	char             *argument,
     	char             *extra)
@@ -318,7 +315,7 @@ ysp_add(clixon_yang_yacc *yy,
     if (yn_insert(yn, ys) < 0) /* Insert into hierarchy */
 	goto err; 
     yang_linenum_set(ys, yy->yy_linenum); /* For error/debugging */
-    if (ys_parse_sub(ys, extra) < 0)     /* Check statement-specific syntax */
+    if (ys_parse_sub(ys, yy->yy_name, extra) < 0)     /* Check statement-specific syntax */
 	goto err2; /* dont free since part of tree */
     return ys;
   err:
@@ -657,7 +654,7 @@ identity_substmt : if_feature_stmt   { _PARSE_DEBUG("identity-substmt -> if-feat
               |                      { _PARSE_DEBUG("identity-substmt -> "); }
               ;
 
-base_stmt     : K_BASE identifier_ref_str stmtend
+base_stmt     : K_BASE identifier_ref_arg_str stmtend
 		{ if (ysp_add(_yy, Y_BASE, $2, NULL)== NULL) _YYERROR("base_stmt"); 
                             _PARSE_DEBUG("base-stmt -> BASE identifier-ref-arg-str"); }
               ;
@@ -728,10 +725,10 @@ typedef_substmt : type_stmt          { _PARSE_DEBUG("typedef-substmt -> type-stm
               ;
 
 /* Type */
-type_stmt     : K_TYPE identifier_ref_str ';' 
+type_stmt     : K_TYPE identifier_ref_arg_str ';' 
 	       { if (ysp_add(_yy, Y_TYPE, $2, NULL) == NULL) _YYERROR("type_stmt"); 
 			   _PARSE_DEBUG("type-stmt -> TYPE identifier-ref-arg-str ;");}
-              | K_TYPE identifier_ref_str
+              | K_TYPE identifier_ref_arg_str
 	      { if (ysp_add_push(_yy, Y_TYPE, $2, NULL) == NULL) _YYERROR("type_stmt"); 
 			 }
                 '{' type_body_stmts '}'
@@ -1298,14 +1295,14 @@ anyxml_substmt  : when_stmt          { _PARSE_DEBUG("anyxml-substmt -> when-stmt
               ;
 
 /* uses-stmt = uses-keyword identifier-ref-arg-str */
-uses_stmt     : K_USES identifier_ref_str ';' 
+uses_stmt     : K_USES identifier_ref_arg_str ';' 
 	       { if (ysp_add(_yy, Y_USES, $2, NULL) == NULL) _YYERROR("uses_stmt"); 
-			   _PARSE_DEBUG("uses-stmt -> USES id-arg-str ;"); }
-              | K_USES identifier_ref_str
+			   _PARSE_DEBUG("uses-stmt -> USES identifier-ref-arg-str ;"); }
+              | K_USES identifier_ref_arg_str
 	      { if (ysp_add_push(_yy, Y_USES, $2, NULL) == NULL) _YYERROR("uses_stmt"); }
 	       '{' uses_substmts '}' 
                            { if (ystack_pop(_yy) < 0) _YYERROR("uses_stmt");
-			     _PARSE_DEBUG("uses-stmt -> USES id-arg-str { uses-substmts }"); }
+			     _PARSE_DEBUG("uses-stmt -> USES identifier-ref-arg-str { uses-substmts }"); }
               ;
 
 uses_substmts : uses_substmts uses_substmt 
@@ -1326,12 +1323,12 @@ uses_substmt  : when_stmt            { _PARSE_DEBUG("uses-substmt -> when-stmt")
               ;
 
 /* refine-stmt = refine-keyword sep refine-arg-str */
-refine_stmt   : K_REFINE desc_schema_nodeid_strs ';' 
+refine_stmt   : K_REFINE refine_arg_str ';' 
 	       { if (ysp_add(_yy, Y_REFINE, $2, NULL) == NULL) _YYERROR("refine_stmt"); 
 		   _PARSE_DEBUG("refine-stmt -> REFINE id-arg-str ;"); }
-              | K_REFINE desc_schema_nodeid_strs
+              | K_REFINE refine_arg_str '{' 
 	      { if (ysp_add_push(_yy, Y_REFINE, $2, NULL) == NULL) _YYERROR("refine_stmt"); }
-	       '{' refine_substmts '}' 
+	          refine_substmts '}' 
                            { if (ystack_pop(_yy) < 0) _YYERROR("refine_stmt");
 			       _PARSE_DEBUG("refine-stmt -> REFINE id-arg-str { refine-substmts }"); }
               ;
@@ -1356,21 +1353,28 @@ refine_substmt  : if_feature_stmt  { _PARSE_DEBUG("refine-substmt -> if-feature-
               |                    { _PARSE_DEBUG("refine-substmt -> "); }
               ;
 
-/* uses-augment-stmt = augment-keyword augment-arg-str 
-uses_augment_stmt : K_AUGMENT desc_schema_nodeid_strs
-*/
-uses_augment_stmt : K_AUGMENT string
-                      { if (ysp_add_push(_yy, Y_AUGMENT, $2, NULL) == NULL) _YYERROR("uses_augment_stmt"); }
+/* refine-arg-str      = < a string that matches the rule refine-arg >
+ * @see yang_schema_nodeid_subparse sub-parser
+ */
+refine_arg_str :  string
+                 { $$ = $1;
+     		   _PARSE_DEBUG("refine-arg-str -> < a string that matches the rule refine-arg >"); }
+               ;
+
+/* uses-augment-stmt = augment-keyword uses-augment-arg-str 
+ * Same keyword as in augment-stmt, but here is sub of uses
+ */
+uses_augment_stmt : K_AUGMENT uses_augment_arg_str 
+                    { if (ysp_add_push(_yy, Y_AUGMENT, $2, NULL) == NULL) _YYERROR("uses_augment_stmt"); }
                     '{' augment_substmts '}'
                       { if (ystack_pop(_yy) < 0) _YYERROR("uses_augment_stmt");
-			     _PARSE_DEBUG("uses-augment-stmt -> AUGMENT desc-schema-node-str { augment-substmts }"); }
-
+			     _PARSE_DEBUG("uses-augment-stmt -> AUGMENT uses-augment-arg-str { augment-substmts }"); }
 		    
 /* augment-stmt = augment-keyword sep augment-arg-str 
- * XXX abs-schema-nodeid-str is too difficult, it needs the + semantics
-augment_stmt   : K_AUGMENT abs_schema_nodeid_strs
+ * augment_stmt   : K_AUGMENT abs_schema_nodeid_strs
+ * Same keyword as in uses-augment-stmt, but here is sub of (sub)module
  */
-augment_stmt   : K_AUGMENT string
+augment_stmt   : K_AUGMENT augment_arg_str 
                    { if (ysp_add_push(_yy, Y_AUGMENT, $2, NULL) == NULL) _YYERROR("augment_stmt"); }
 	       '{' augment_substmts '}' 
                    { if (ystack_pop(_yy) < 0) _YYERROR("augment_stmt");
@@ -1396,6 +1400,22 @@ augment_substmt : when_stmt          { _PARSE_DEBUG("augment-substmt -> when-stm
               |                      { _PARSE_DEBUG("augment-substmt -> "); }
               ;
 
+/* augment-arg-str = < a string that matches the rule augment-arg >
+ * @see yang_schema_nodeid_subparse sub-parser
+ */
+augment_arg_str :  string
+                 { $$ = $1;
+     		   _PARSE_DEBUG("augment-arg-str -> < a string that matches the rule augment-arg >"); }
+               ;
+
+/* uses-augment-arg-str = < a string that matches the rule uses-augment-arg >
+ * @see yang_schema_nodeid_subparse sub-parser
+ */
+uses_augment_arg_str :  string
+                 { $$ = $1;
+     		   _PARSE_DEBUG("uses-augment-arg-str -> < a string that matches the rule uses-augment-arg >"); }
+               ;
+
 /* when */
 when_stmt   : K_WHEN string ';' 
 	       { if (ysp_add(_yy, Y_WHEN, $2, NULL) == NULL) _YYERROR("when_stmt"); 
@@ -1799,6 +1819,8 @@ output_stmt  : K_OUTPUT  /* XXX reuse input-substatements since they are same */
 		       _PARSE_DEBUG("output-stmt -> OUTPUT { input-substmts }"); }
               ;
 
+/* XXX this is not the "string" rule in Section 14, rather it is the string as described in 6.1 
+ */
 string        : qstrings { $$=$1;
 		   _PARSE_DEBUG("string -> qstrings"); } 
               | ustring  { $$=$1;
@@ -1844,54 +1866,6 @@ ustring       : ustring CHARS
                       {  _PARSE_DEBUG1("ustring-> ERRCHARS(%s)", $1); _YYERROR("Invalid string chars"); }
               ;
 
-abs_schema_nodeid : abs_schema_nodeid '/' node_identifier
-                 {
-		     if (($$=clixon_string_del_join($1, "/", $3)) == NULL) _YYERROR("abs_schema_nodeid");
-		     free($3);
-		     _PARSE_DEBUG("absolute-schema-nodeid -> absolute-schema-nodeid / node-identifier"); }
-              | '/' node_identifier
-                 {
-		     if (($$=clixon_string_del_join(NULL, "/", $2)) == NULL) _YYERROR("abs_schema_nodeid");
-		     free($2);
-		     _PARSE_DEBUG("absolute-schema-nodeid -> / node-identifier"); }
-              ;
-
-desc_schema_nodeid_strs : desc_schema_nodeid_strs '+' desc_schema_nodeid_str
-                     {
-			 int len = strlen($1);
-			 $$ = realloc($1, len + strlen($3) + 1); 
-			 sprintf($$+len, "%s", $3);
-			 free($3); 
-			 _PARSE_DEBUG("desc-schema-nodeid-strs-> desc-schema-nodeid-strs + desc-schema-nodeid-str");
-		     }
-                      | desc_schema_nodeid_str
-                           { $$=$1;
-			       _PARSE_DEBUG("desc-schema-nodeid-strs-> desc-schema-nodeid-str"); }
-                      ;
-
-desc_schema_nodeid_str : desc_schema_nodeid
-                         { $$=$1;
-			     _PARSE_DEBUG("descendant-schema-nodeid-str -> descendant-schema-nodeid"); }
-                     | '"' desc_schema_nodeid '"'
-                         { $$=$2;
-			     _PARSE_DEBUG("descendant-schema-nodeid-str -> \" descendant-schema-nodeid \" "); }
-                     | '\'' desc_schema_nodeid '\''
-                         { $$=$2;
-			     _PARSE_DEBUG("descendant-schema-nodeid-str -> ' descendant-schema-nodeid '"); }
-
-;
-
-/* descendant-schema-nodeid */
-desc_schema_nodeid : node_identifier
-                     { $$= $1;
-			 _PARSE_DEBUG("descendant-schema-nodeid -> node_identifier"); }
-                   | node_identifier abs_schema_nodeid
-		   {
-		       if (($$=clixon_string_del_join($1, "", $2)) == NULL) _YYERROR("desc_schema_nodeid");
-		       free($2);
-		       _PARSE_DEBUG("descendant-schema-nodeid -> node_identifier abs_schema_nodeid"); }
-                   ;
-
 identifier_str : '"' IDENTIFIER '"' { $$ = $2;
  		         _PARSE_DEBUG("identifier_str -> \" IDENTIFIER \" ");}
                | '\'' IDENTIFIER '\'' { $$ = $2;
@@ -1900,14 +1874,6 @@ identifier_str : '"' IDENTIFIER '"' { $$ = $2;
 		         _PARSE_DEBUG("identifier_str -> IDENTIFIER ");}
                ;
 
-identifier_ref_str : '"' identifier_ref '"' { $$ = $2;
-		   _PARSE_DEBUG("identifier_ref_str -> \" identifier_ref \" ");}
-               | '\'' identifier_ref '\'' { $$ = $2;
-		   _PARSE_DEBUG("identifier_ref_str -> ' identifier_ref ' ");}
-               | identifier_ref           { $$ = $1;
-		   _PARSE_DEBUG("identifier_ref_str -> identifier_ref ");}
-               ;
-
 integer_value_str : '"' INT '"' { $$=$2; }
                   | '\'' INT '\'' { $$=$2; }
                   |     INT     { $$=$1; }
@@ -1922,21 +1888,14 @@ bool_str       : '"' BOOL '"' { $$ = $2;
                ;
 
 
-/*   node-identifier     = [prefix ":"] identifier */
-node_identifier : IDENTIFIER
-		   { $$=$1;
-		       _PARSE_DEBUG("identifier-ref-arg-str -> string"); }
-                | IDENTIFIER ':' IDENTIFIER
-		{
-		    if (($$=clixon_string_del_join($1, ":", $3)) == NULL) _YYERROR("node_identifier");
-		    free($3);
-		    _PARSE_DEBUG("identifier-ref-arg-str -> prefix : string"); }
-                ;
-
 /* ;;; Basic Rules */
 
-/* identifier-ref = [prefix ":"] identifier */
-identifier_ref : node_identifier { $$=$1;}
+/* identifier-ref-arg-str      = < a string that matches the rule idenetifier-ref-arg >
+ * @see yang_schema_nodeid_subparse sub-parser
+ */
+identifier_ref_arg_str :  string
+                 { $$ = $1;
+     		   _PARSE_DEBUG("identifier-ref-arg-str -> < a string that matches the rule identifier-ref-arg >"); }
                ;
 
 /*   optsep = *(WSP / line-break) */
diff --git a/lib/src/clixon_yang_parse_lib.c b/lib/src/clixon_yang_parse_lib.c
index 255972f9..8d6947d4 100644
--- a/lib/src/clixon_yang_parse_lib.c
+++ b/lib/src/clixon_yang_parse_lib.c
@@ -97,7 +97,7 @@
 #include "clixon_yang_cardinality.h"
 #include "clixon_plugin.h"
 #include "clixon_yang_internal.h"
-#include "clixon_yang_parse_sub.h"
+#include "clixon_yang_sub_parse.h"
 #include "clixon_yang_parse_lib.h"
 
 /* Size of json read buffer when reading from file*/
@@ -562,7 +562,7 @@ yang_expand_uses_node(yang_stmt *yn,
 	    goto done;
     }
     /* Make a copy of the grouping, then make refinements to this copy
-     * Note this ygrouping2 object does not gave a parent and does not work in many
+     * Note this ygrouping2 object does not have a parent and does not work in many
      * functions which assume a full hierarchy, use the original ygrouping in those cases.
      */
     if ((ygrouping2 = ys_dup(ygrouping)) == NULL)
@@ -600,6 +600,11 @@ yang_expand_uses_node(yang_stmt *yn,
 	if (xml_nsctx_yang(ywhen, &wnsc) < 0)
 	    goto done;
     }
+    /* Note: yang_desc_schema_nodeid() requires ygrouping2 to be in yspec tree,
+     * cannot be dangling, insert into tree here and then prune immediately after while loop
+     */
+    if (yn_insert(yang_parent_get(ygrouping), ygrouping2) < 0)
+	goto done;
     /* Iterate through refinements and modify grouping copy 
      * See RFC 7950 7.13.2 yrt is the refine target node
      */
@@ -609,7 +614,7 @@ yang_expand_uses_node(yang_stmt *yn,
 	if (yang_keyword_get(yr) != Y_REFINE)
 	    continue;
 	/* Find a node */
-	if (yang_desc_schema_nodeid(ygrouping, /* Cannot use ygrouping2 */
+	if (yang_desc_schema_nodeid(ygrouping2,
 				    yang_argument_get(yr),
 				    &yrt) < 0)
 	    goto done;
@@ -622,10 +627,10 @@ yang_expand_uses_node(yang_stmt *yn,
 	/* Do the actual refinement */
 	if (ys_do_refine(yr, yrt) < 0)
 	    goto done;
-	/* RFC: The argument is a string that identifies a node in the 
-	 * grouping.  I interpret that as only one node --> break */
-	break;
     } /* while yr */
+    /* Note: prune here to make dangling again after while loop */
+    if (ys_prune_self(ygrouping2) < 0)
+	goto done;
     /* Then copy and insert each child element from ygrouping2 to yn */
     k=0;
     for (j=0; j<yang_len_get(ygrouping2); j++){
@@ -1862,8 +1867,11 @@ 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). Is consumed
+ * @param[in] ys       yang statement
+ * @param[in] filename Name of parsed file, if any
+ * @param[in] extra    Yang extra for cornercases (unknown/extension). Is consumed
+ * @retval    0        OK
+ * @retval   -1        Error
  *
  * 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)
@@ -1873,8 +1881,9 @@ ys_parse(yang_stmt   *ys,
  * @see ys_populate
  */
 int
-ys_parse_sub(yang_stmt *ys,
-	     char      *extra)
+ys_parse_sub(yang_stmt  *ys,
+	     const char *filename,
+	     char       *extra)
 {
     int        retval = -1;
     uint8_t    fd;
@@ -1885,10 +1894,19 @@ ys_parse_sub(yang_stmt *ys,
     int        ret;
     uint32_t   minmax;
     cg_var    *cv = NULL;
+    yang_stmt *yp;
     
     arg = yang_argument_get(ys);
     keyword = yang_keyword_get(ys);
     switch (keyword){
+    case Y_BASE:
+    case Y_TYPE:
+    case Y_USES:
+	/* Invoke next level parser 
+	 */
+	if (yang_schema_nodeid_subparse(yang_argument_get(ys), YA_ID_REF, filename, yang_linenum_get(ys)) < 0)
+	    goto done;
+	break;
     case Y_FRACTION_DIGITS:
 	if (ys_parse(ys, CGV_UINT8) == NULL) 
 	    goto done;
@@ -1962,7 +1980,23 @@ ys_parse_sub(yang_stmt *ys,
 	 * pass 1 is not yet resolved, only check syntax, actual feature check made in next pass
 	 * @see yang_features
 	 */
-	if (yang_if_feature_parse(yang_argument_get(ys), NULL, yang_linenum_get(ys), NULL) < 0)
+	if (yang_subparse(yang_argument_get(ys), ys, YA_IF_FEATURE, filename, yang_linenum_get(ys), NULL) < 0)
+	    goto done;
+	break;
+    case Y_AUGMENT: /* If parent is module/submodule: absolute-schema-nodeid
+		     * If parent is uses: descendant-schema-nodeid 
+		     */
+	if ((yp = yang_parent_get(ys)) &&
+	    yang_keyword_get(yp) != Y_USES){
+	    if (yang_schema_nodeid_subparse(yang_argument_get(ys), YA_ABS_SCHEMANODEID, filename, yang_linenum_get(ys)) < 0)
+		goto done;
+	    break;
+	}
+	// fall through
+    case Y_REFINE:
+	/* Invoke next level parser on refine-arg-str / descendant-schema-nodeid
+	 */
+	if (yang_schema_nodeid_subparse(yang_argument_get(ys), YA_DESC_SCHEMANODEID, filename, yang_linenum_get(ys)) < 0)
 	    goto done;
 	break;
     case Y_UNKNOWN:{ /* save (optional) argument in ys_cv */
diff --git a/lib/src/clixon_if_feature_parse.h b/lib/src/clixon_yang_schemanode_parse.h
similarity index 71%
rename from lib/src/clixon_if_feature_parse.h
rename to lib/src/clixon_yang_schemanode_parse.h
index 5b9905b9..67c9945b 100644
--- a/lib/src/clixon_if_feature_parse.h
+++ b/lib/src/clixon_yang_schemanode_parse.h
@@ -31,36 +31,37 @@
 
   ***** END LICENSE BLOCK *****
 
- * if-feature-expr RFC7950 14
+ * decendant-schema-nodeid RFC7950 14
  */
-#ifndef _CLIXON_IF_FEATURE_PARSE_H_
-#define _CLIXON_IF_FEATURE_PARSE_H_
+#ifndef _CLIXON_YANG_SCHEMANODE_PARSE_H_
+#define _CLIXON_YANG_SCHEMANODE_PARSE_H_
 
 /*
  * Types
  */
 /*! XML parser yacc handler struct */
-struct clixon_if_feature_parse_yacc {
+struct clixon_yang_schemanode_parse_yacc {
     char      *if_parse_string; /* original (copy of) parse string */
+    const char *if_mainfile;     /* Original main-file (this is a sib-parser) */
     int        if_linenum;      /* Number of \n in parsed buffer */
     void      *if_lexbuf;       /* Internal parse buffer from lex */
     yang_stmt *if_ys;           /* Yang statement, NULL if no check */
-    int        if_enabled;      /* Result: 0: feature disabled, 1: enabled */
+    enum yang_sub_parse_accept if_accept;
 };
-typedef struct clixon_if_feature_parse_yacc clixon_if_feature_yacc;
+typedef struct clixon_yang_schemanode_parse_yacc clixon_yang_schemanode_yacc;
 
 /*
  * Variables
  */
-extern char *clixon_if_feature_parsetext;
+extern char *clixon_yang_schemanode_parsetext;
 
 /*
  * Prototypes
  */
-int clixon_if_feature_parsel_init(clixon_if_feature_yacc *ya);
-int clixon_if_feature_parsel_exit(clixon_if_feature_yacc *ya);
-int clixon_if_feature_parsel_linenr(void);
-int clixon_if_feature_parselex(void *);
-int clixon_if_feature_parseparse(void *);
+int clixon_yang_schemanode_parsel_init(clixon_yang_schemanode_yacc *ya);
+int clixon_yang_schemanode_parsel_exit(clixon_yang_schemanode_yacc *ya);
+int clixon_yang_schemanode_parsel_linenr(void);
+int clixon_yang_schemanode_parselex(void *);
+int clixon_yang_schemanode_parseparse(void *);
 
-#endif	/* _CLIXON_IF_FEATURE_PARSE_H_ */
+#endif	/* _CLIXON_YANG_SCHEMANODE_PARSE_H_ */
diff --git a/lib/src/clixon_yang_schemanode_parse.l b/lib/src/clixon_yang_schemanode_parse.l
new file mode 100644
index 00000000..eab18699
--- /dev/null
+++ b/lib/src/clixon_yang_schemanode_parse.l
@@ -0,0 +1,113 @@
+/*
+ *
+  ***** BEGIN LICENSE BLOCK *****
+ 
+  Copyright (C) 2022 Olof Hagsand and Rubicon Communications, LLC(Netgate)
+
+  This file is part of CLIXON.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+  Alternatively, the contents of this file may be used under the terms of
+  the GNU General Public License Version 3 or later (the "GPL"),
+  in which case the provisions of the GPL are applicable instead
+  of those above. If you wish to allow use of your version of this file only
+  under the terms of the GPL, and not to allow others to
+  use your version of this file under the terms of Apache License version 2, 
+  indicate your decision by deleting the provisions above and replace them with
+  the  notice and other provisions required by the GPL. If you do not delete
+  the provisions above, a recipient may use your version of this file under
+  the terms of any one of the Apache License version 2 or the GPL.
+
+  ***** END LICENSE BLOCK *****
+
+ * decendant-schema-nodeid RFC7950 14
+ */
+
+%{
+
+#include "clixon_config.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "clixon_yang_schemanode_parse.tab.h"   /* generated file */
+
+/* cligen */
+#include <cligen/cligen.h>
+
+/* clicon */
+#include "clixon_queue.h"
+#include "clixon_hash.h"
+#include "clixon_handle.h"
+#include "clixon_yang.h"
+#include "clixon_xml.h"
+#include "clixon_yang_sub_parse.h"
+#include "clixon_yang_schemanode_parse.h"
+
+/* Redefine main lex function so that you can send arguments to it: _if is added to arg list */
+#define YY_DECL int clixon_yang_schemanode_parselex(void *_if)
+
+/* Dont use input function (use user-buffer) */
+#define YY_NO_INPUT
+
+/* typecast macro */
+#define _IF ((clixon_yang_schemanode_yacc *)_if) 
+
+#undef clixon_xml_parsewrap
+int clixon_yang_schemanode_parsewrap(void)
+{
+  return 1;
+}
+
+/*
+ */
+
+%}
+
+identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
+
+%%
+
+<INITIAL>\n               { _IF->if_linenum++; return *yytext; }
+<INITIAL>:                { return *yytext; }
+<INITIAL>\/               { return *yytext; }
+<INITIAL>{identifier}     { clixon_yang_schemanode_parselval.string = strdup(yytext);
+                            return IDENTIFIER;}
+<INITIAL><<EOF>>          { return MY_EOF; }
+<INITIAL>.                { return -1; }
+
+%%
+
+/*! Initialize XML scanner.
+ */
+int
+clixon_yang_schemanode_parsel_init(clixon_yang_schemanode_yacc *ife)
+{
+  BEGIN(INITIAL);
+  ife->if_lexbuf = yy_scan_string (ife->if_parse_string);
+  if (0)
+    yyunput(0, "");  /* XXX: just to use unput to avoid warning  */
+  return 0;
+}
+
+/*! Exit xml scanner */
+int
+clixon_yang_schemanode_parsel_exit(clixon_yang_schemanode_yacc *ife)
+{
+   yy_delete_buffer(ife->if_lexbuf);
+   clixon_yang_schemanode_parselex_destroy();  /* modern */
+
+  return 0;
+}
diff --git a/lib/src/clixon_yang_schemanode_parse.y b/lib/src/clixon_yang_schemanode_parse.y
new file mode 100644
index 00000000..a793cd60
--- /dev/null
+++ b/lib/src/clixon_yang_schemanode_parse.y
@@ -0,0 +1,198 @@
+/*
+ *
+  ***** BEGIN LICENSE BLOCK *****
+ 
+  Copyright (C) 2022 Olof Hagsand and Rubicon Communications, LLC(Netgate)
+
+  This file is part of CLIXON.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+  Alternatively, the contents of this file may be used under the terms of
+  the GNU General Public License Version 3 or later (the "GPL"),
+  in which case the provisions of the GPL are applicable instead
+  of those above. If you wish to allow use of your version of this file only
+  under the terms of the GPL, and not to allow others to
+  use your version of this file under the terms of Apache License version 2, 
+  indicate your decision by deleting the provisions above and replace them with
+  the  notice and other provisions required by the GPL. If you do not delete
+  the provisions above, a recipient may use your version of this file under
+  the terms of any one of the Apache License version 2 or the GPL.
+
+  ***** END LICENSE BLOCK *****
+
+  Just syntax check, return no data
+
+ * descendant-schema-nodeid RFC7950 14
+   descendant-schema-nodeid = node-identifier
+                         [absolute-schema-nodeid]
+
+   absolute-schema-nodeid = 1*("/" node-identifier)
+
+   node-identifier     = [prefix ":"] identifier
+
+   prefix              = identifier
+   identifier          = (ALPHA / "_")
+                         *(ALPHA / DIGIT / "_" / "-" / ".")
+
+ */
+%union {
+    char *string;
+    void *stack;
+    int number;
+}
+
+%token MY_EOF
+%token <string>   IDENTIFIER
+
+%start top
+
+%lex-param     {void *_if} /* Add this argument to parse() and lex() function */
+%parse-param   {void *_if}
+
+%{
+/* Here starts user C-code */
+    
+/* typecast macro */
+#define _IF ((clixon_yang_schemanode_yacc *)_if)
+#define _YYERROR(msg) {clicon_err(OE_YANG, 0, "%s", (msg)); YYERROR;}
+    
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+#include <stdlib.h>
+
+/* cligen */
+#include <cligen/cligen.h>
+
+/* clicon */
+#include "clixon_err.h"
+#include "clixon_log.h"
+#include "clixon_queue.h"
+#include "clixon_hash.h"
+#include "clixon_string.h"
+#include "clixon_handle.h"
+#include "clixon_yang.h"
+#include "clixon_xml.h"
+#include "clixon_yang_module.h"
+#include "clixon_xml_vec.h"
+#include "clixon_data.h"
+#include "clixon_yang_sub_parse.h"
+#include "clixon_yang_schemanode_parse.h"
+
+/* Enable for debugging, steals some cycles otherwise */
+#if 1
+#define _PARSE_DEBUG(s) clicon_debug(1,(s))
+#else
+#define _PARSE_DEBUG(s)
+#endif
+ 
+void 
+clixon_yang_schemanode_parseerror(void *arg,
+				  char *s) 
+{
+    clixon_yang_schemanode_yacc *ife = (clixon_yang_schemanode_yacc *)arg;
+
+    clicon_err_fn(NULL, 0, OE_YANG, 0, "yang_schemanode_parse: file:%s:%d \"%s\" %s: at or before: %s", 
+	       ife->if_mainfile,
+	       ife->if_linenum,
+	       ife->if_parse_string,
+	       s,
+	       clixon_yang_schemanode_parsetext); 
+    return;
+}
+
+%} 
+ 
+%%
+
+/* See RFC 7950 Sec 14 refine-arg-str / usage-augment-arg-str */
+top        : descendant_schema_nodeid MY_EOF
+                    {
+			_PARSE_DEBUG("top->descendant-schema-nodeid");
+			if (_IF->if_accept == YA_DESC_SCHEMANODEID){
+			    YYACCEPT;
+			}
+			else{
+			    _YYERROR("descendant-schema-nodeid unexpected"); 
+			}
+		    }
+           | absolute_schema_nodeid MY_EOF
+                    {
+			_PARSE_DEBUG("top->absolute-schema-nodeid");
+			if (_IF->if_accept == YA_ABS_SCHEMANODEID){
+			    YYACCEPT;
+			}
+			else{
+			    _YYERROR("absolute-schema-nodeid unexpected"); 
+			}
+		    }
+           ;
+
+descendant_schema_nodeid
+           : node_identifier
+                    {
+			_PARSE_DEBUG("descendant-schema-nodeid->node-identifier");
+		    }
+           | node_identifier absolute_schema_nodeid
+	            {
+			_PARSE_DEBUG("descendant-schema-nodeid->absolute-schema-nodeid");
+		    }
+           ;
+
+absolute_schema_nodeid
+           : absolute_schema_nodeid '/'  node_identifier 
+                    {
+			_PARSE_DEBUG("absolute-schema-nodeid->absolute-schema-nodeid '/' node-identifier");
+		    }
+           | '/'  node_identifier 
+	            {
+			_PARSE_DEBUG("absolute-schema-nodeid->'/' node-identifier");
+		    }
+           ;
+
+/*   node-identifier     = [prefix ":"] identifier */
+node_identifier : identifier
+		   {
+		       _PARSE_DEBUG("node-identifier -> identifier");
+		       if (_IF->if_accept == YA_ID_REF){
+			   YYACCEPT;
+		       }
+		   }
+                | prefix ':' identifier
+		{
+		    _PARSE_DEBUG("node_identifier -> prefix : identifier");
+		    if (_IF->if_accept == YA_ID_REF){
+			YYACCEPT;
+		    }
+		}
+                ;
+
+prefix   : IDENTIFIER
+		{
+		    _PARSE_DEBUG("prefix -> IDENTIFIER");
+		    free($1);
+		}
+         ;
+
+identifier : IDENTIFIER
+		{
+		    _PARSE_DEBUG("identifier -> IDENTIFIER");
+		    free($1);
+		}
+         ;
+
+%%
+
diff --git a/lib/src/clixon_yang_parse_sub.c b/lib/src/clixon_yang_sub_parse.c
similarity index 50%
rename from lib/src/clixon_yang_parse_sub.c
rename to lib/src/clixon_yang_sub_parse.c
index bf164930..1f3b5c13 100644
--- a/lib/src/clixon_yang_parse_sub.c
+++ b/lib/src/clixon_yang_sub_parse.c
@@ -54,34 +54,41 @@
 #include "clixon_hash.h"
 #include "clixon_handle.h"
 #include "clixon_yang.h"
-#include "clixon_if_feature_parse.h"
+#include "clixon_yang_sub_parse.h"
+#include "clixon_yang_schemanode_parse.h"
 
-/*! Invoke yang if-feature sub-parser on string
+/*! Invoke yang sub-parser on string
  *
- * @param[in]  str      If-feature-expr string
- * @param[in]  ys       Yang if-feature statement
- * @param[in]  linenum  Line number context
- * @param[out] enabled  0: Disabled, 1: Enabled
- * @retval     0        OK
- * @retval    -1        Error
+ * @param[in]  str           yang string
+ * @param[in]  ys            Yang statement
+ * @param[in]  accept        Sub-parse rule to accept
+ * @param[in]  mainfile      Name of main parse file
+ * @param[in]  linenum       Line number context in mainfile (assume parse module of ys)
+ * @param[out] enabled       0: Disabled, 1: Enabled (if present)
+ * @retval     0             OK
+ * @retval    -1             Error
  */
 int
-yang_if_feature_parse(char      *str,
-		      yang_stmt *ys,
-		      int        linenum,
-		      int       *enabled)
+yang_subparse(char                      *str,
+	      yang_stmt                 *ys,
+	      enum yang_sub_parse_accept accept,
+	      const char                *mainfile,
+	      int                        linenum,
+	      int                       *enabled)
 {
     int                    retval = -1;
-    clixon_if_feature_yacc ife = {0,};
+    clixon_yang_sub_parse_yacc ife = {0,};
 
     clicon_debug(2, "%s %s", __FUNCTION__, str);
     ife.if_parse_string = str;
     ife.if_linenum = linenum;
-    ife.if_ys = ys;
-    if (clixon_if_feature_parsel_init(&ife) < 0)
+    if (enabled)
+	ife.if_ys = ys; /* Used as trigger to check if enabled */
+    ife.if_accept = accept;
+    ife.if_mainfile = mainfile;
+    if (clixon_yang_sub_parsel_init(&ife) < 0)
 	goto done;
-    if (clixon_if_feature_parseparse(&ife) != 0) { /* yacc returns 1 on error */
-	clicon_log(LOG_NOTICE, "If-feature error: line %d str:%s", ife.if_linenum, str);
+    if (clixon_yang_sub_parseparse(&ife) != 0) { /* yacc returns 1 on error */
 	if (clicon_errno == 0)
 	    clicon_err(OE_YANG, 0, "If-feature parser error with no error code (should not happen)");
 	goto done;
@@ -90,6 +97,43 @@ yang_if_feature_parse(char      *str,
 	*enabled = ife.if_enabled;
     retval = 0;
  done:
-    clixon_if_feature_parsel_exit(&ife);
+    clixon_yang_sub_parsel_exit(&ife);
+    return retval;
+}
+
+/*! Invoke yang (absolute_/descendant-)schema-nodeid sub-parser on string
+ *
+ * Used for  refine-arg-str / usage-augment-arg-str in RFC 7950 Sec 14
+ * @param[in]  str      (abs/desc)_schema_nodeid string
+ * @param[in]  accept        Sub-parse rule to accept
+ * @param[in]  mainfile Name of main parse file
+ * @param[in]  linenum  Line number context in mainfile
+ * @retval     0        OK
+ * @retval    -1        Error
+ */
+int
+yang_schema_nodeid_subparse(char                      *str,
+			    enum yang_sub_parse_accept accept,
+			    const char                *mainfile,
+			    int                        linenum)
+{
+    int                         retval = -1;
+    clixon_yang_schemanode_yacc ife = {0,};
+
+    clicon_debug(1, "%s %s", __FUNCTION__, str);
+    ife.if_parse_string = str;
+    ife.if_linenum = linenum;
+    ife.if_mainfile = mainfile;
+    ife.if_accept = accept; /* accept absolute-schema-nodeid */
+    if (clixon_yang_schemanode_parsel_init(&ife) < 0)
+	goto done;
+    if (clixon_yang_schemanode_parseparse(&ife) != 0) { /* yacc returns 1 on error */
+	if (clicon_errno == 0)
+	    clicon_err(OE_YANG, 0, "descendant-schema-nodeid parser error with no error code (should not happen)");
+	goto done;
+    }
+    retval = 0;
+ done:
+    clixon_yang_schemanode_parsel_exit(&ife);
     return retval;
 }
diff --git a/lib/src/clixon_yang_parse_sub.h b/lib/src/clixon_yang_sub_parse.h
similarity index 51%
rename from lib/src/clixon_yang_parse_sub.h
rename to lib/src/clixon_yang_sub_parse.h
index 4e906635..e8c18ad9 100644
--- a/lib/src/clixon_yang_parse_sub.h
+++ b/lib/src/clixon_yang_sub_parse.h
@@ -33,12 +33,47 @@
 
  * Sub-parsers to upper-level YANG parser: everything that is "stringified"
  */
-#ifndef _CLIXON_YANG_PARSE_SUB_H_
-#define _CLIXON_YANG_PARSE_SUB_H_
+#ifndef _CLIXON_YANG_SUB_PARSE_H_
+#define _CLIXON_YANG_SUB_PARSE_H_
+
+/*
+ * Types
+ */
+/*! Sub-parse rule to accept */
+enum yang_sub_parse_accept{
+    YA_IF_FEATURE,
+    YA_ID_REF,
+    YA_ABS_SCHEMANODEID,
+    YA_DESC_SCHEMANODEID
+};
+
+/*! XML parser yacc handler struct */
+struct clixon_yang_sub_parse_yacc {
+    char       *if_parse_string; /* original (copy of) parse string */
+    const char *if_mainfile;     /* Original main-file (this is a sib-parser) */
+    int         if_linenum;      /* Number of \n in parsed buffer (in mainfile) */
+    void      *if_lexbuf;       /* Internal parse buffer from lex */
+    yang_stmt *if_ys;           /* Yang statement, NULL if no check */
+    enum yang_sub_parse_accept if_accept; /* Which sub-parse rule to accept */ 
+    int         if_enabled;      /* Result: 0: feature disabled, 1: enabled */
+};
+typedef struct clixon_yang_sub_parse_yacc clixon_yang_sub_parse_yacc;
+
+/*
+ * Variables
+ */
+extern char *clixon_yang_sub_parsetext;
 
 /*
  * Prototypes
  */
-int  yang_if_feature_parse(char *str, yang_stmt *ys, int linenum, int *enabled);
+int clixon_yang_sub_parsel_init(clixon_yang_sub_parse_yacc *ya);
+int clixon_yang_sub_parsel_exit(clixon_yang_sub_parse_yacc *ya);
+int clixon_yang_sub_parsel_linenr(void);
+int clixon_yang_sub_parselex(void *);
+int clixon_yang_sub_parseparse(void *);
 
-#endif	/* _CLIXON_YANG_PARSER_SUB_H_ */
+int  yang_subparse(char *str, yang_stmt *ys, enum yang_sub_parse_accept accept, const char *mainfile, int linenum, int *enabled);
+int  yang_schema_nodeid_subparse(char *str, enum yang_sub_parse_accept accept, const char *mainfile, int linenum);
+
+#endif	/* _CLIXON_YANG_SUB_PARSER_H_ */
diff --git a/lib/src/clixon_if_feature_parse.l b/lib/src/clixon_yang_sub_parse.l
similarity index 81%
rename from lib/src/clixon_if_feature_parse.l
rename to lib/src/clixon_yang_sub_parse.l
index bfa413e4..5d9b2adf 100644
--- a/lib/src/clixon_if_feature_parse.l
+++ b/lib/src/clixon_yang_sub_parse.l
@@ -42,7 +42,7 @@
 #include <string.h>
 #include <stdint.h>
 
-#include "clixon_if_feature_parse.tab.h"   /* generated file */
+#include "clixon_yang_sub_parse.tab.h"   /* generated file */
 
 /* cligen */
 #include <cligen/cligen.h>
@@ -53,19 +53,19 @@
 #include "clixon_handle.h"
 #include "clixon_yang.h"
 #include "clixon_xml.h"
-#include "clixon_if_feature_parse.h"
+#include "clixon_yang_sub_parse.h"
 
 /* Redefine main lex function so that you can send arguments to it: _if is added to arg list */
-#define YY_DECL int clixon_if_feature_parselex(void *_if)
+#define YY_DECL int clixon_yang_sub_parselex(void *_if)
 
 /* Dont use input function (use user-buffer) */
 #define YY_NO_INPUT
 
 /* typecast macro */
-#define _IF ((clixon_if_feature_yacc *)_if) 
+#define _IF ((clixon_yang_sub_parse_yacc *)_if) 
 
 #undef clixon_xml_parsewrap
-int clixon_if_feature_parsewrap(void)
+int clixon_yang_sub_parsewrap(void)
 {
   return 1;
 }
@@ -78,19 +78,21 @@ int clixon_if_feature_parsewrap(void)
 %x COMMENT
 %x STRING
 
+identifier      [A-Za-z_][A-Za-z0-9_\-\.]*
+
 %%
 
 <INITIAL>[ \t\r]*         { return SEP; }
 <INITIAL>\n               { _IF->if_linenum++; return SEP; }
 <INITIAL>\(               { return *yytext; }
 <INITIAL>\)               { return *yytext; }
+<INITIAL>:                { return *yytext; }
 <INITIAL>not              { return NOT; }
 <INITIAL>and              { return AND; }
 <INITIAL>or               { return OR; }
+<INITIAL>{identifier}     { clixon_yang_sub_parselval.string = strdup(yytext);
+                            return IDENTIFIER;}
 <INITIAL><<EOF>>          { return MY_EOF; }
-<INITIAL>[^\n\r \t\(\)]+  {
-                            clixon_if_feature_parselval.string = strdup(yytext);
-                            return TOKEN; }
 <INITIAL>.                { return -1; }
 
 %%
@@ -98,7 +100,7 @@ int clixon_if_feature_parsewrap(void)
 /*! Initialize XML scanner.
  */
 int
-clixon_if_feature_parsel_init(clixon_if_feature_yacc *ife)
+clixon_yang_sub_parsel_init(clixon_yang_sub_parse_yacc *ife)
 {
   BEGIN(INITIAL);
   ife->if_lexbuf = yy_scan_string (ife->if_parse_string);
@@ -109,10 +111,10 @@ clixon_if_feature_parsel_init(clixon_if_feature_yacc *ife)
 
 /*! Exit xml scanner */
 int
-clixon_if_feature_parsel_exit(clixon_if_feature_yacc *ife)
+clixon_yang_sub_parsel_exit(clixon_yang_sub_parse_yacc *ife)
 {
    yy_delete_buffer(ife->if_lexbuf);
-   clixon_if_feature_parselex_destroy();  /* modern */
+   clixon_yang_sub_parselex_destroy();  /* modern */
 
   return 0;
 }
diff --git a/lib/src/clixon_if_feature_parse.y b/lib/src/clixon_yang_sub_parse.y
similarity index 73%
rename from lib/src/clixon_if_feature_parse.y
rename to lib/src/clixon_yang_sub_parse.y
index d04175a8..80d7ed1a 100644
--- a/lib/src/clixon_if_feature_parse.y
+++ b/lib/src/clixon_yang_sub_parse.y
@@ -31,7 +31,7 @@
 
   ***** END LICENSE BLOCK *****
 
- * if-feature-expr RFC7950 14
+  * Sub-parser for if-feature AND identifier-ref as defined in RFC7950 Section 14
    if-feature-expr     = if-feature-term
                            [sep or-keyword sep if-feature-expr]
 
@@ -41,8 +41,14 @@
    if-feature-factor   = not-keyword sep if-feature-factor /
                          "(" optsep if-feature-expr optsep ")" /
                          identifier-ref-arg
+   identifier-ref-arg  = identifier-ref
+   identifier-ref      = [prefix ":"] identifier
+   prefix              = identifier
+   identifier          = (ALPHA / "_")
+                         *(ALPHA / DIGIT / "_" / "-" / ".")
+
   Called twice:
-  1. In parsing just for syntac checks (dont do feature-check)
+  1. In parsing just for syntax checks (dont do feature-check)
   2. In populate when all yangs are resolved, then do semantic feature-check
  */
 %union {
@@ -55,10 +61,11 @@
 %token AND
 %token NOT
 %token OR
-%token <string> TOKEN
+%token <string> IDENTIFIER
 %token SEP
 
 %type <number> if_feature_factor if_feature_expr
+%type <string> identifier_ref identifier prefix
 
 %start top
 
@@ -68,8 +75,9 @@
 %{
 
 /* typecast macro */
-#define _IF ((clixon_if_feature_yacc *)_if)
-
+#define _IF ((clixon_yang_sub_parse_yacc *)_if)
+#define _YYERROR(msg) {clicon_err(OE_YANG, 0, "%s", (msg)); YYERROR;}
+    
 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
@@ -92,7 +100,7 @@
 #include "clixon_yang_module.h"
 #include "clixon_xml_vec.h"
 #include "clixon_data.h"
-#include "clixon_if_feature_parse.h"
+#include "clixon_yang_sub_parse.h"
 
 /* Enable for debugging, steals some cycles otherwise */
 #if 0
@@ -102,15 +110,17 @@
 #endif
     
 void 
-clixon_if_feature_parseerror(void *arg,
+clixon_yang_sub_parseerror(void *arg,
 			     char *s) 
 {
-    clixon_if_feature_yacc *ife = (clixon_if_feature_yacc *)arg;
+    clixon_yang_sub_parse_yacc *ife = (clixon_yang_sub_parse_yacc *)arg;
 
-    clicon_err(OE_XML, XMLPARSE_ERRNO, "if_feature_parse: line %d: %s: at or before: %s", 
+    clicon_err_fn(NULL, 0, OE_YANG, 0, "yang_sub_parse: file:%s:%d \"%s\" %s: at or before: %s", 
+	       ife->if_mainfile,
 	       ife->if_linenum,
+	       ife->if_parse_string,
 	       s,
-	       clixon_if_feature_parsetext); 
+	       clixon_yang_sub_parsetext); 
     return;
 }
 
@@ -119,8 +129,8 @@ clixon_if_feature_parseerror(void *arg,
  * @param[in]  ys   If-feature type yang node
  */
 static int
-if_feature_check(char      *str,
-		 yang_stmt *ys)
+if_feature_check(clixon_yang_sub_parse_yacc *ife,
+		 char                       *str)
 {
     int         retval = -1;
     char       *prefix = NULL;
@@ -128,8 +138,9 @@ if_feature_check(char      *str,
     yang_stmt  *ymod;  /* module yang node */
     yang_stmt  *yfeat; /* feature yang node */
     cg_var     *cv;
+    yang_stmt  *ys;
     
-    if (ys == NULL)
+    if ((ys = ife->if_ys) == NULL)
 	return 0;
     if (nodeid_split(str, &prefix, &feature) < 0)
 	goto done;
@@ -172,7 +183,12 @@ top        : if_feature_expr MY_EOF
                     {
 			_PARSE_DEBUG("top->if-feature-expr");
 			_IF->if_enabled = $1;
-			YYACCEPT;
+			if (_IF->if_accept == YA_IF_FEATURE){
+			    YYACCEPT;
+			}
+			else{
+			    _YYERROR("Expected if-feature-expr"); 
+			}
 		    }
            ;
 
@@ -199,10 +215,9 @@ if_feature_factor   : NOT sep1 if_feature_factor
            | '(' optsep if_feature_expr optsep ')'
 		                   { _PARSE_DEBUG("if-feature-factor-> ( optsep if-feature-expr optsep )");
 		                     $$ = $3; }
-           | TOKEN                 {
-	       _PARSE_DEBUG("if-feature-factor-> TOKEN");
-	       if (_IF->if_ys == NULL) $$ = 0;
-	       else if (($$ = if_feature_check($1, _IF->if_ys)) < 0) {
+           | identifier_ref  {
+	       _PARSE_DEBUG("if-feature-factor-> identifier-ref");
+	       if (($$ = if_feature_check(_IF, $1)) < 0) {
 		   free($1);
 		   YYERROR;
 	       }
@@ -210,6 +225,42 @@ if_feature_factor   : NOT sep1 if_feature_factor
 	     }
            ;
 
+/*   identifier-ref     = [prefix ":"] identifier */
+identifier_ref : identifier
+		   {
+		       // XXX memory leak?
+		       _PARSE_DEBUG("identifier-ref -> identifier");
+			if (_IF->if_accept == YA_ID_REF){
+			    YYACCEPT;
+			}
+		       $$=$1;
+		   }
+                | prefix ':' identifier
+		{
+		    if (($$=clixon_string_del_join($1, ":", $3)) == NULL) _YYERROR("identifier_ref");
+		    free($3);
+		    if (_IF->if_accept == YA_ID_REF){
+			YYACCEPT;
+		    }
+		    _PARSE_DEBUG("identifier-ref -> prefix : identifier");
+		}
+                ;
+
+prefix   : IDENTIFIER
+		{
+		    _PARSE_DEBUG("prefix -> IDENTIFIER");
+		    $$=$1;
+
+		}
+         ;
+
+identifier : IDENTIFIER
+		{
+		    _PARSE_DEBUG("identifier -> IDENTIFIER");
+		    $$=$1;
+		}
+         ;
+
 optsep     : sep1                  { _PARSE_DEBUG("optsep->sep"); }
            |                       { _PARSE_DEBUG("optsep->"); }
            ;
diff --git a/test/test_refine.sh b/test/test_refine.sh
new file mode 100755
index 00000000..5e4db71c
--- /dev/null
+++ b/test/test_refine.sh
@@ -0,0 +1,121 @@
+#!/usr/bin/env bash
+# yang refine
+# See eg ietf-tls-server@2022-05-04.yang container certificate :
+# 1. dual refine
+# 2. refine argument is non-trivial descendant-schema-nodeid stretching over a choice/case
+# 3. refine "str1" + "str2" i.e. split refine-arg-str
+#
+# Magic line must be first in script (see README.md)
+s="$_" ; . ./lib.sh || if [ "$s" = $0 ]; then exit 0; else return 0; fi
+
+APPNAME=example
+
+cfg=$dir/conf_yang.xml
+fyang=$dir/clixon-example.yang
+
+cat <<EOF > $cfg
+<clixon-config xmlns="http://clicon.org/config">
+  <CLICON_CONFIGFILE>$cfg</CLICON_CONFIGFILE>
+  <CLICON_YANG_DIR>$dir</CLICON_YANG_DIR>
+  <CLICON_YANG_DIR>${YANG_INSTALLDIR}</CLICON_YANG_DIR>
+  <CLICON_YANG_MAIN_FILE>$fyang</CLICON_YANG_MAIN_FILE>
+  <CLICON_CLISPEC_DIR>/usr/local/lib/$APPNAME/clispec</CLICON_CLISPEC_DIR>
+  <CLICON_CLI_DIR>/usr/local/lib/$APPNAME/cli</CLICON_CLI_DIR>
+  <CLICON_CLI_MODE>$APPNAME</CLICON_CLI_MODE>
+  <CLICON_SOCK>/usr/local/var/$APPNAME/$APPNAME.sock</CLICON_SOCK>
+  <CLICON_BACKEND_PIDFILE>/usr/local/var/$APPNAME/$APPNAME.pidfile</CLICON_BACKEND_PIDFILE>
+  <CLICON_XMLDB_DIR>/usr/local/var/$APPNAME</CLICON_XMLDB_DIR>
+  <CLICON_YANG_LIBRARY>true</CLICON_YANG_LIBRARY>
+</clixon-config>
+EOF
+
+# This is the main module where the augment exists
+cat <<EOF > $fyang
+module clixon-example {
+   yang-version 1.1;
+   namespace "urn:example:clixon";
+   prefix ex;
+
+   /* see ietf-keystore@2022-05-24.yang */
+   grouping mygrouping {
+    choice mykeystore {
+      mandatory true;
+      case local {
+        container local-definition {
+	  presence true;
+	  leaf dummy1{
+            type string;
+	   default "foo1";	
+	  }
+        }
+      }
+      case keystore {
+        container keystore-reference {
+	  presence true;
+	  leaf dummy2{
+            type string;
+	   default "bar1";	
+	  }
+        }
+      }
+    }
+  }
+  container certificate {
+     description  "See ietf-tls-server@2022-05-24.yang";
+     uses ex:mygrouping{
+        refine "mykeystore/local/local-definition/dummy1" {
+	   default "foo2";
+        }
+        refine "mykeystore/keystore/keystore-reference"
+                   + "/dummy2" {
+	   default "bar2";
+           }
+        }
+    }
+}
+
+EOF
+
+new "test params: -f $cfg"
+
+if [ $BE -ne 0 ]; then
+    new "kill old backend"
+    sudo clixon_backend -zf $cfg
+
+    if [ $? -ne 0 ]; then
+	err
+    fi
+    new "start backend -s init -f $cfg"
+    start_backend -s init -f $cfg
+fi
+
+new "wait backend"
+wait_backend
+
+new "Set local-definition"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><certificate xmlns=\"urn:example:clixon\"><local-definition/></certificate></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
+new "Get config expected foo2 refined default value"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><get-config><source><candidate/></source></get-config></rpc>" "" "<rpc-reply $DEFAULTNS><data><certificate xmlns=\"urn:example:clixon\"><local-definition><dummy1>foo2</dummy1></local-definition></certificate></data></rpc-reply>"
+
+new "Set keystore-reference"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><certificate xmlns=\"urn:example:clixon\"><keystore-reference/></certificate></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
+new "Get config expected bar2 refined default value"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><get-config><source><candidate/></source></get-config></rpc>" "" "<rpc-reply $DEFAULTNS><data><certificate xmlns=\"urn:example:clixon\"><keystore-reference><dummy2>bar2</dummy2></keystore-reference></certificate></data></rpc-reply>"
+
+if [ $BE -ne 0 ]; then
+    new "Kill backend"
+    # Check if premature kill
+    pid=$(pgrep -u root -f clixon_backend)
+    if [ -z "$pid" ]; then
+	err "backend already dead"
+    fi
+    # kill backend
+    stop_backend -f $cfg
+fi
+
+rm -rf $dir
+
+new "endtest"
+endtest
diff --git a/test/test_type.sh b/test/test_type.sh
index a4bf15d3..e957b16e 100755
--- a/test/test_type.sh
+++ b/test/test_type.sh
@@ -36,8 +36,7 @@ module example3{
      type union {
        type w;
        type enumeration {
-         enum "bounded";
-         enum "un bounded"; /* note w space */
+         enum bounded;
        }
      }
   }
@@ -272,9 +271,6 @@ EOF
     new "cli validate"
     expectpart "$($clixon_cli -1f $cfg -l o -l o validate)" 0 '^$'
 
-    new "cli set transitive union string (and space)"
-    expectpart "$($clixon_cli -1f $cfg -l o set c ulle "un\ bounded")" 0 '^$'
-
     new "cli validate"
     expectpart "$($clixon_cli -1f $cfg -l o -l o validate)" 0 '^$'
 
diff --git a/test/test_union.sh b/test/test_union.sh
index 840fc092..f6d3cf20 100755
--- a/test/test_union.sh
+++ b/test/test_union.sh
@@ -38,7 +38,7 @@ module example3{
           range "4..44";
        }
        type enumeration {
-         enum "unbounded";
+         enum unbounded;
        }
      }
   }