diff --git a/other-notations/YARSpg.ebnf b/other-notations/YARSpg.ebnf
index d814d56..2ecafc5 100644
--- a/other-notations/YARSpg.ebnf
+++ b/other-notations/YARSpg.ebnf
@@ -7,7 +7,7 @@
  https://github.com/lszeremeta/antlr-yarspg
  
  [The "BSD licence"]
- Copyright (c) 2018-2020, Łukasz Szeremeta (@ University of Bialystok, https://lukasz.science)
+ Copyright (c) 2018-2021, Łukasz Szeremeta (@ University of Bialystok, https://github.com/lszeremeta)
  Copyright (c) 2018-2019, Dominik Tomaszuk (@ University of Bialystok, http://www.uwb.edu.pl/)
  All rights reserved.
 
@@ -52,10 +52,10 @@ var_declaration
          ::= var '=' prop ( ',' prop )*
 var_declaration_schema
          ::= var '=' prop_schema ( ',' prop_schema )*
-var_name ::= ALNUM_PLUS
+var_name ::= ID
 graph_id
          ::= 'default'
-           | ALNUM_PLUS
+           | ID
 local_metadata
          ::= '+' prop_list
 prop_list
@@ -74,11 +74,11 @@ section  ::= '%' SECTION_NAME
 directed ::= '(' node_id ')' '-' '(' edge_id? ( '{' ( edge_label ( ',' edge_label )* )? '}' )? prop_list? ')' '->' '(' node_id ')' graphs_list? local_metadata?
 undirected
          ::= '(' node_id ')' '-' '(' edge_id? ( '{' ( edge_label ( ',' edge_label )* )? '}' )? prop_list? ')' '-' '(' node_id ')' graphs_list? local_metadata?
-node_id  ::= ALNUM_PLUS
+node_id  ::= ID
 node_label
          ::= STRING
 prop     ::= key ':' value meta_prop*       
-edge_id   ::= ALNUM_PLUS
+edge_id   ::= ID
 edge_label
          ::= STRING
 graph_label
@@ -98,7 +98,7 @@ struct   ::= '{' key ':' ( primitive_value | struct ) meta_prop* ( ',' key ':' (
 node_schema
          ::= 'S' '(' node_id_schema ( '{' ( node_label ( ',' node_label )* )? '}' )? prop_list_schema? ')' graphs_list? local_metadata?
 node_id_schema
-         ::= ALNUM_PLUS
+         ::= ID
 prop_list_schema
          ::= '[' ( ( prop_schema | var ) ( ',' ( prop_schema | var ) )* )? ']'
 prop_schema
@@ -159,14 +159,6 @@ COMMENT  ::= '#' [^#xd#xa#xc]*
 STRING   ::= '"' ([^"\#xd#xa] | "'" | '\"')* '"'
 UNSIGNED_INT
          ::= [0-9]*
-ALNUM_PLUS
-         ::= PN_CHARS_BASE ((PN_CHARS | '.')* PN_CHARS)?
-PN_CHARS ::= PN_CHARS_U
-           | [-0-9#xB7#x0300-#x036F#x203F-#x2040]
-PN_CHARS_U
-         ::= PN_CHARS_BASE
-           | '_'
-PN_CHARS_BASE
-         ::= [A-Za-z0-9#xC0-#xD6#xD8-#xF6#xF8-#x2FF#x370-#x37D#x37F-#x1FFF#x200C-#x200D#x2070-#x218F#x2C00-#x2FEF#x3001-#xD7FF#xF900-#xFDCF#xFDF0-#xFFFD]
+ID       ::= [a-zA-Z_][a-zA-Z0-9_]*
 HEX      ::= [0-9A-Fa-f]
 WS       ::= ([#x20#x9#xa])+
\ No newline at end of file
diff --git a/yarspg/YARSpg.g4 b/yarspg/YARSpg.g4
index a44cbc9..21aaf49 100644
--- a/yarspg/YARSpg.g4
+++ b/yarspg/YARSpg.g4
@@ -1,6 +1,6 @@
 /*
  [The "BSD licence"]
- Copyright (c) 2018-2020, Łukasz Szeremeta (@ University of Bialystok, https://lukasz.science)
+ Copyright (c) 2018-2021, Łukasz Szeremeta (@ University of Bialystok, https://github.com/lszeremeta)
  Copyright (c) 2018, Dominik Tomaszuk (@ University of Bialystok, http://www.uwb.edu.pl/)
  Copyright (c) 2018, Karol Litman (@ University of Bialystok, http://www.uwb.edu.pl/)
  All rights reserved.
@@ -60,12 +60,12 @@ var_declaration_schema
     ;
 
 var_name
-    : ALNUM_PLUS
+    : ID
     ;
 
 graph_id
     : 'default'
-    | ALNUM_PLUS
+    | ID
     ;
 
 local_metadata
@@ -110,7 +110,7 @@ undirected
     ;
 
 node_id
-    : ALNUM_PLUS
+    : ID
     ;
 
 node_label
@@ -122,7 +122,7 @@ prop
     ;
 
 edge_id
-    : ALNUM_PLUS
+    : ID
     ;
 
 edge_label
@@ -169,7 +169,7 @@ node_schema
     ;
 
 node_id_schema
-    : ALNUM_PLUS
+    : ID
     ;
 
 prop_list_schema
@@ -281,20 +281,8 @@ UNSIGNED_INT
     : [0-9]+
     ;
 
-ALNUM_PLUS
-    : PN_CHARS_BASE ((PN_CHARS | '.')* PN_CHARS)?
-    ;
-
-PN_CHARS
-    : PN_CHARS_U | '-' | [0-9] | '\u00B7' | [\u0300-\u036F] | [\u203F-\u2040]
-    ;
-
-PN_CHARS_U
-    : PN_CHARS_BASE | '_'
-    ;
-
-PN_CHARS_BASE
-    : 'A' .. 'Z' | 'a' .. 'z' | '0' .. '9' | '\u00C0' .. '\u00D6' | '\u00D8' .. '\u00F6' | '\u00F8' .. '\u02FF' | '\u0370' .. '\u037D' | '\u037F' .. '\u1FFF' | '\u200C' .. '\u200D' | '\u2070' .. '\u218F' | '\u2C00' .. '\u2FEF' | '\u3001' .. '\uD7FF' | '\uF900' .. '\uFDCF' | '\uFDF0' .. '\uFFFD'
+ID
+    : [a-zA-Z_][a-zA-Z0-9_]*
     ;
     
 HEX
diff --git a/yarspg/examples/test-example.yarspg b/yarspg/examples/test-example.yarspg
index 1dbe3ab..c3d854e 100644
--- a/yarspg/examples/test-example.yarspg
+++ b/yarspg/examples/test-example.yarspg
@@ -73,9 +73,9 @@ S(NS9 {"label"}["keyword": Struct(String)@"ok": Integer])
 S(NS92 {"label"}["keyword": Struct(String)@"ok": Integer OPTIONAL])
 (i {"label"}["keyword": {"name": "abc"@"info": "ok", "title": "xyz"}@"ok": "1"])
 S(NS10 {"2label4"}["keyword2": Struct(Struct(String))])
-(2i44 {"2label4"}["keyword2": {"names": {"name": "abc", "title": "xyz"}, "names2": {"name2": "abc2", "title2": "xyz2"}, "names3": {"name3": "abc3", "title3": "xyz3"}}])
+(a2i44 {"2label4"}["keyword2": {"names": {"name": "abc", "title": "xyz"}, "names2": {"name2": "abc2", "title2": "xyz2"}, "names3": {"name3": "abc3", "title3": "xyz3"}}])
 S(NS11 {"2label4"}["keyword2": Struct(Struct(String)@"struct": String)@"struct": String @"ok": Bool])
-(2i44 {"2label4"}["keyword2": {"names": {"name": "abc", "title": "xyz"}@"rating": "5", "names2": {"name2": "abc2"@"more": "ok", "title2": "xyz2"}, "names3": {"name3": "abc3", "title3": "xyz3"}@"struct": "inside"}@"struct": "outside" @"ok": "true"])
+(a2i44 {"2label4"}["keyword2": {"names": {"name": "abc", "title": "xyz"}@"rating": "5", "names2": {"name2": "abc2"@"more": "ok", "title2": "xyz2"}, "names3": {"name3": "abc3", "title3": "xyz3"}@"struct": "inside"}@"struct": "outside" @"ok": "true"])
 (i2 {"label"}["keyword": {"name": "abc", "title": {"name2": "abc2", "title2": "xyz2"}}])
 S(NS12 {"432f"}["set": Set(String)])/graphname/
 (z {"432f"}["set": {"name", "title"}])/graphname/
@@ -83,16 +83,17 @@ S(NS12 {"432f"}["set": Set(String)])/graphname/
 S(NS13 {"432f2"}["set": Set(Set(String))])
 (z2 {"432f2"}["set": {{"set2", "title"}}])
 S(NS14 {"3432f2"}["set": Set(Set(String))])
-(3z2 {"3432f2"}["set": {{"set2", "title"}, {"set3", "title3"}}])
+(z3z2 {"3432f2"}["set": {{"set2", "title"}, {"set3", "title3"}}])
 S(NS15 {"1ad32"}["list": List(String)])
-(1dsc {"1ad32"}["list": ["name55", "name3"]])
+(c1dsc {"1ad32"}["list": ["name55", "name3"]])
 S(NS16 {"1ad32"}["list": List(String NULL)])
 S(NS163 {"1ad32"}["list": List(String MAX 3)])
 S(NS164 {"1ad32"}["list": List(String MIN 1)])
 S(NS165 {"1ad32"}["list": List(String MAX 1)])
-(1dsc {"1ad32"}["list": ["name55", "null"]])
+(c1dsc {"1ad32"}["list": ["name55", "null"]])
 S(NS17 {"1ad32"}["list": List(String) NULL])
-(1dsc {"1ad32"}["list": "null"])
+(c1dsc {"1ad32"}["list": "null"])
+(_test {"1ad32"}["list": "null"])
 S(NS18 {"ad3"}["list": List(List(String))])
 (ds {"ad3"}["list": [["name55", "name3"]]])
 S(NS19 {"ad32"}["list": List(List(String))])