diff --git a/tool/src/org/antlr/v4/tool/ErrorType.java b/tool/src/org/antlr/v4/tool/ErrorType.java
index 51e17fcc2..74a621528 100644
--- a/tool/src/org/antlr/v4/tool/ErrorType.java
+++ b/tool/src/org/antlr/v4/tool/ErrorType.java
@@ -33,13 +33,11 @@ import org.antlr.v4.Tool;
 
 /**
  * A complex enumeration of all the error messages that the tool can issue.
- *
+ * <p/>
  * When adding error messages, also add a description of the message to the
  * Wiki with a location under the Wiki page
  * <a href="http://www.antlr.org/wiki/display/ANTLR4/Errors+Reported+by+the+ANTLR+Tool">Errors Reported by the ANTLR Tool</a>.
  *
- * TODO: add notion of single issuance of an error; some don't need to be repeated; AST_OP_IN_ALT_WITH_REWRITE and option issues
- *
  * @author Jim Idle <jimi@temporal-wave.com>, Terence Parr
  * @since 4.0
  */
@@ -119,14 +117,14 @@ public enum ErrorType {
 	INVALID_LEXER_SET_ELEMENT(134, "lexer set element <arg> is invalid (either lexer rule ref or literal with > 1 char)", ErrorSeverity.ERROR),
 
 	// Backward incompatibility errors
-	V3_TREE_GRAMMAR(200, "tree grammars are not supported in ANTLR v4", ErrorSeverity.ERROR),
-	V3_LEXER_LABEL(201, "labels in lexer rules are not supported in ANTLR v4; " +
+	V3_TREE_GRAMMAR(200, "tree grammars are not supported in ANTLR 4", ErrorSeverity.ERROR),
+	V3_LEXER_LABEL(201, "labels in lexer rules are not supported in ANTLR 4; " +
 		"actions cannot reference elements of lexical rules but you can use " +
 		"getText() to get the entire text matched for the rule", ErrorSeverity.WARNING_ONE_OFF),
-	V3_TOKENS_SYNTAX(202, "'tokens {A; B;}' syntax is now 'tokens {A, B}' in ANTLR v4", ErrorSeverity.WARNING),
-	V3_ASSIGN_IN_TOKENS(203, "assignments in tokens{} are not supported in ANTLR v4; use lexical rule '<arg> : <arg2>;' instead", ErrorSeverity.ERROR_ONE_OFF),
-	V3_GATED_SEMPRED(204, "{...}?=> gate semantic predicates in v3 behave like normal predicates in ANTLR v4; use {...}? instead", ErrorSeverity.WARNING_ONE_OFF),
-	V3_SYNPRED(205, "(...)=> syntactic predicates are not needed or supported ANTLR v4; just delete them", ErrorSeverity.ERROR_ONE_OFF),
+	V3_TOKENS_SYNTAX(202, "'tokens {A; B;}' syntax is now 'tokens {A, B}' in ANTLR 4", ErrorSeverity.WARNING),
+	V3_ASSIGN_IN_TOKENS(203, "assignments in tokens{} are not supported in ANTLR 4; use lexical rule '<arg> : <arg2>;' instead", ErrorSeverity.ERROR_ONE_OFF),
+	V3_GATED_SEMPRED(204, "{...}?=> explicitly gated semantic predicates are deprecated in ANTLR 4; use {...}? instead", ErrorSeverity.WARNING_ONE_OFF),
+	V3_SYNPRED(205, "(...)=> syntactic predicates are not supported in ANTLR 4", ErrorSeverity.ERROR_ONE_OFF),
 
     // Dependency sorting errors