CLDR-17179 Flag n/a as forbidden value in CheckForExemplars (#4541)

Author: btangmu

tools/cldr-code/src/main/java/org/unicode/cldr/test/CheckCLDR.java

@@ -939,7 +939,8 @@ public enum Subtype {
             nullOrEmptyValue,
             ttsAnnotationMissing,
             illegalCharacter,
-            missingNumberingSystem;
+            missingNumberingSystem,
+            forbiddenValue;
 
             @Override
             public String toString() {

tools/cldr-code/src/main/java/org/unicode/cldr/test/CheckForExemplars.java

@@ -20,6 +20,8 @@
 import com.ibm.icu.text.Transform;
 import com.ibm.icu.text.UnicodeSet;
 import com.ibm.icu.util.ULocale;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.BitSet;
 import java.util.Date;
 import java.util.HashMap;
@@ -63,9 +65,18 @@ public class CheckForExemplars extends FactoryCheckCLDR {
 
     private static final String STAND_IN = "#";
 
-    // private final UnicodeSet commonAndInherited = new
-    // UnicodeSet(CheckExemplars.Allowed).complement();
-    // "[[:script=common:][:script=inherited:][:alphabetic=false:]]");
+    /**
+     * These values, and their uppercase variants, are forbidden for any path. They should all be
+     * lowercase.
+     */
+    private static final List<String> FORBIDDEN_VALUES = new ArrayList<>(Arrays.asList("n/a"));
+
+    private static final String FORBIDDEN_VALUE_MESSAGE =
+            "This value is forbidden for any path. If you believe this item is not an error, "
+                    + "add a forum post with an explanation about why this value is not an error. "
+                    + "The CLDR Technical Committee will reply to your forum post if they need any more information in "
+                    + "order to resolve the error or next steps on how to resolve if they still believe it is an error.";
+
     static String[] EXEMPLAR_SKIPS = {
         "/currencySpacing",
         "/exemplarCharacters",
@@ -329,7 +340,13 @@ public CheckCLDR handleCheck(
         }
 
         // Check all paths for illegal characters, even EXEMPLAR_SKIPS
-        checkIllegalCharacters(path, value, result);
+        checkIllegalCharacters(value, result);
+
+        // If you believe this item is not an error, add forum post with an explanation about why
+        // the current value is not an error. The CLDR Technical Committee will reply to your forum
+        // post if they need any more information in order to resolve the error or next steps on how
+        // to resolve if they still believe it is an error
+        checkForbiddenValues(value, result);
 
         if (containsPart(path, EXEMPLAR_SKIPS)) {
             return this;
@@ -583,7 +600,7 @@ public CheckCLDR handleCheck(
 
     // Check for characters that are always illegal in values.
     // Currently those are just the paired bidi marks.
-    private void checkIllegalCharacters(String path, String value, List<CheckStatus> result) {
+    private void checkIllegalCharacters(String value, List<CheckStatus> result) {
         if (ILLEGAL_RTL_CONTROLS.containsSome(value)) {
             result.add(
                     new CheckStatus()
@@ -595,6 +612,17 @@ private void checkIllegalCharacters(String path, String value, List<CheckStatus>
         }
     }
 
+    private void checkForbiddenValues(String value, List<CheckStatus> result) {
+        if (FORBIDDEN_VALUES.contains(value.toLowerCase())) {
+            result.add(
+                    new CheckStatus()
+                            .setCause(this)
+                            .setMainType(CheckStatus.errorType)
+                            .setSubtype(Subtype.forbiddenValue)
+                            .setMessage(FORBIDDEN_VALUE_MESSAGE));
+        }
+    }
+
     private String checkAndReplacePlaceholders(
             String path, String value, List<CheckStatus> result) {
         CheckStatus.Type statusType =