Index: TagChecker.java
===================================================================
--- TagChecker.java	(revision 14484)
+++ TagChecker.java	(working copy)
@@ -197,6 +197,8 @@
                 BufferedReader reader = cf.getContentReader()
             ) {
                 String okValue = null;
+                String okLine = null;
+                boolean bad = false;
                 boolean tagcheckerfile = false;
                 boolean ignorefile = false;
                 boolean isFirstLine = true;
@@ -203,6 +205,7 @@
                 String line;
                 while ((line = reader.readLine()) != null && (tagcheckerfile || !line.isEmpty())) {
                     if (line.startsWith("#")) {
+                        System.out.println(line);
                         if (line.startsWith("# JOSM TagChecker")) {
                             tagcheckerfile = true;
                             if (!DEFAULT_SOURCES.contains(source)) {
@@ -254,9 +257,21 @@
                             }
                         }
                     } else if (line.charAt(0) == '+') {
+                        okLine = line;
                         okValue = line.substring(1);
+                        bad = false;
                     } else if (line.charAt(0) == '-' && okValue != null) {
-                        harmonizedKeys.put(harmonizeKey(line.substring(1)), okValue);
+                        String hk =  harmonizeKey(line.substring(1));
+                        if (!okValue.equals(hk)) {
+                            if (!bad) {
+                                bad = true;
+                                System.out.println(okLine);
+                            }
+                            if (harmonizedKeys.put(hk, okValue) == null) {
+                                System.out.println(line);
+                            }
+
+                        }
                     } else {
                         Logging.error(tr("Invalid spellcheck line: {0}", line));
                     }