diff --git a/src/main/java/net/hostsharing/hsadminng/config/MessageTranslator.java b/src/main/java/net/hostsharing/hsadminng/config/MessageTranslator.java
index b179dcf3..3bcbbda5 100644
--- a/src/main/java/net/hostsharing/hsadminng/config/MessageTranslator.java
+++ b/src/main/java/net/hostsharing/hsadminng/config/MessageTranslator.java
@@ -1,5 +1,7 @@
 package net.hostsharing.hsadminng.config;
 
+import lombok.extern.slf4j.Slf4j;
+import lombok.val;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.MessageSource;
 import org.springframework.stereotype.Service;
@@ -10,6 +12,7 @@ import java.util.Locale;
 
 @Service
 @RequestScope
+@Slf4j
 public class MessageTranslator {
 
     @Autowired
@@ -21,19 +24,26 @@ public class MessageTranslator {
     public String translateTo(final Locale locale, final String messageKey, final Object... args) {
         try {
             // we don't use the method which also takes a default message right away ...
-            final var translatedMessage = messageSource.getMessage(messageKey, args, locale);
+            val translatedMessage = messageSource.getMessage(messageKey, args, locale);
             return translatedMessage;
         } catch (final Exception e) {
-            final var defaultMessage = messageKey.replace("'", "''");
-            final var translatedMessage = messageSource.getMessage(messageKey, args, defaultMessage, locale);
-            if (locale != Locale.ENGLISH) {
-                // ... because we want to add a hint that the translation is missing, even if placeholders got replaced
-                return translatedMessage + " [" + locale + " translation missing]";
-            }
-            return translatedMessage;
+            // ... but log the missing translation ...
+            log.error("Missing translation for message key '{}' in locale '{}'", messageKey, locale, e);
+
+            // and decorate the default message to mark it as not really translated:
+            val defaultMessage = messageKey.substring(messageKey.indexOf('.') + 1)
+                    .replaceAll("--+", " - ")
+                    .replaceAll("(?<! )-(?! )", " ")
+                    .replace("'", "''");
+            val fallbackMessage = messageSource.getMessage(messageKey, args, defaultMessage, Locale.ENGLISH);
+            return decorateMissingTranslation(fallbackMessage);
         }
     }
 
+    private static String decorateMissingTranslation(final String translatedMessage) {
+        return "【⍰" + translatedMessage + "⍰】";
+    }
+
     public String translate(final String messageKey, final Object... args) {
         return translateTo(httpRequest.getLocale(), messageKey, args);
     }
diff --git a/src/main/java/net/hostsharing/hsadminng/config/MessagesResourceConfig.java b/src/main/java/net/hostsharing/hsadminng/config/MessagesResourceConfig.java
index 18111ea1..840a0dc9 100644
--- a/src/main/java/net/hostsharing/hsadminng/config/MessagesResourceConfig.java
+++ b/src/main/java/net/hostsharing/hsadminng/config/MessagesResourceConfig.java
@@ -11,6 +11,8 @@ public class MessagesResourceConfig {
         final var source = new ResourceBundleMessageSource();
         source.setBasenames("i18n/messages");
         source.setDefaultEncoding("UTF-8");
+        source.setFallbackToSystemLocale(false);
+        source.setUseCodeAsDefaultMessage(false);
         return source;
     }
 
diff --git a/src/main/java/net/hostsharing/hsadminng/config/RealCasAuthenticator.java b/src/main/java/net/hostsharing/hsadminng/config/RealCasAuthenticator.java
index 18c5d0f1..5f55bda7 100644
--- a/src/main/java/net/hostsharing/hsadminng/config/RealCasAuthenticator.java
+++ b/src/main/java/net/hostsharing/hsadminng/config/RealCasAuthenticator.java
@@ -57,7 +57,7 @@ public class RealCasAuthenticator implements CasAuthenticator {
 
     private Document verifyServiceTicket(final String serviceTicket) throws SAXException, IOException, ParserConfigurationException {
         if ( !serviceTicket.startsWith("ST-") ) {
-            throwBadCredentialsException("unknown authorization ticket");
+            throwBadCredentialsException("auth.unknown-authorization-ticket");
         }
 
         final var url = casServerUrl + "/cas/p3/serviceValidate" +
@@ -74,7 +74,7 @@ public class RealCasAuthenticator implements CasAuthenticator {
     private String extractUserName(final Document verification) {
 
         if (verification.getElementsByTagName("cas:authenticationSuccess").getLength() == 0) {
-            throwBadCredentialsException("CAS service-ticket could not be verified");
+            throwBadCredentialsException("auth.cas-service-ticket-could-not-be-verified");
         }
         return verification.getElementsByTagName("cas:user").item(0).getTextContent();
     }
diff --git a/src/main/java/net/hostsharing/hsadminng/errors/ReferenceNotFoundException.java b/src/main/java/net/hostsharing/hsadminng/errors/ReferenceNotFoundException.java
index ef4d6d22..c207685a 100644
--- a/src/main/java/net/hostsharing/hsadminng/errors/ReferenceNotFoundException.java
+++ b/src/main/java/net/hostsharing/hsadminng/errors/ReferenceNotFoundException.java
@@ -8,7 +8,7 @@ import static java.util.Locale.ENGLISH;
 
 public class ReferenceNotFoundException extends RuntimeException {
 
-    private final String TRANSLATABLE_MESSAGE = "{0} \"{1}\" not found";
+    private final String TRANSLATABLE_MESSAGE = "general.{0}-{1}-not-found";
 
     private final MessageTranslator translator;
 
diff --git a/src/main/java/net/hostsharing/hsadminng/errors/RestResponseEntityExceptionHandler.java b/src/main/java/net/hostsharing/hsadminng/errors/RestResponseEntityExceptionHandler.java
index 13a74701..3e701ffc 100644
--- a/src/main/java/net/hostsharing/hsadminng/errors/RestResponseEntityExceptionHandler.java
+++ b/src/main/java/net/hostsharing/hsadminng/errors/RestResponseEntityExceptionHandler.java
@@ -156,7 +156,7 @@ public class RestResponseEntityExceptionHandler
     }
 
     private Function<FieldError, String> toEnrichedFieldErrorMessage() {
-        final var translatedButIsLiteral = messageTranslator.translate("but is");
+        final var translatedButIsLiteral = messageTranslator.translate("general.but-is");
         // TODO.i18n: the following does not work in all languages, e.g. not in right-to-left languages
         return fieldError -> fieldError.getField() + " " + fieldError.getDefaultMessage() +
                 " " + translatedButIsLiteral + " " + optionallyQuoted(fieldError.getRejectedValue());
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/accounts/CredentialContextResourceToEntityMapper.java b/src/main/java/net/hostsharing/hsadminng/hs/accounts/CredentialContextResourceToEntityMapper.java
index 225ee95a..a0ab46e1 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/accounts/CredentialContextResourceToEntityMapper.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/accounts/CredentialContextResourceToEntityMapper.java
@@ -52,13 +52,15 @@ public class CredentialContextResourceToEntityMapper {
                 final var existingContextEntity = em.find(HsCredentialsContextRealEntity.class, resource.getUuid());
                 if (existingContextEntity == null) {
                     throw new EntityNotFoundException(
-                            messageTranslator.translate("{0} \"{1}\" not found or not accessible",
+                            messageTranslator.translate(
+                                    "general.{0}-{1}-not-found-or-not-accessible",
                                     "credentials uuid", resource.getUuid()));
                 }
                 if ((resource.getType() != null && !existingContextEntity.getType().equals(resource.getType())) ||
                     (resource.getQualifier() != null && !existingContextEntity.getQualifier().equals(resource.getQualifier()))) {
                     throw new EntityNotFoundException(
-                            messageTranslator.translate("existing {0} does not match given resource {1}",
+                            messageTranslator.translate(
+                                    "credentials.existing-{0}-does-not-match-given-resource-{1}",
                                     existingContextEntity, resource));
                 }
                 entities.add(existingContextEntity);
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsController.java b/src/main/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsController.java
index 52e52c7e..23de6056 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsController.java
@@ -203,12 +203,12 @@ public class HsCredentialsController implements CredentialsApi {
     private void validate(final HsCredentialsEntity newCredentialsEntity) {
         // the referenced person must be represented by currently logged in person
         final var personUuid = newCredentialsEntity.getPerson().getUuid();
-        final var representedPersonUuids = rbacPersonRepo.findPersonsrepresentedByPersonWithUuid(personUuid)
+        final var representedPersonUuids = rbacPersonRepo.findPersonsRepresentedByPersonWithUuid(personUuid)
                 .stream().map(HsOfficePerson::getUuid).toList();
         if ( !representedPersonUuids.contains(personUuid)) {
             throw new ValidationException(
                     messageTranslator.translate(
-                            "access-denied-personUuid-{0}-not-represented-by-currently-logged-in-person",
+                            "credentials.access-denied-person-uuid-{0}-not-represented-by-currently-logged-in-person",
                             personUuid));
         }
     }
@@ -224,7 +224,7 @@ public class HsCredentialsController implements CredentialsApi {
     private List<HsCredentialsEntity> findByPersonUuid(final UUID personUuid) {
         final var person = rbacPersonRepo.findByUuid(personUuid).orElseThrow(
                 () -> new EntityNotFoundException(
-                        messageTranslator.translate("{0} \"{1}\" not found or not accessible", "personUuid", personUuid)
+                        messageTranslator.translate("general.{0}-{1}-not-found-or-not-accessible", "personUuid", personUuid)
                 )
 
         );
@@ -269,7 +269,7 @@ public class HsCredentialsController implements CredentialsApi {
     final BiConsumer<CredentialsInsertResource, HsCredentialsEntity> RESOURCE_TO_ENTITY_POSTMAPPER = (resource, entity) -> {
         final var person = rbacPersonRepo.findByUuid(resource.getPersonUuid()).orElseThrow(
                 () -> new EntityNotFoundException(
-                        messageTranslator.translate("{0} \"{1}\" not found or not accessible", "personUuid", resource.getPersonUuid())
+                        messageTranslator.translate("general.{0}-{1}-not-found-or-not-accessible", "personUuid", resource.getPersonUuid())
                 )
         );
 
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsCoopAssetTranslations.java b/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsCoopAssetTranslations.java
index d61f59ed..f64c33d1 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsCoopAssetTranslations.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsCoopAssetTranslations.java
@@ -17,7 +17,7 @@ public class HsCoopAssetTranslations implements RetroactiveTranslator {
 
     @Override
     public boolean canTranslate(final String message) {
-        return message.equals("ERROR: [400] coop assets transaction would result in a negative balance of assets");
+        return message.equals("ERROR: [400] office.coop-assets.transaction-would-result-in-a-negative-balance-of-assets");
     }
 
     @Override
@@ -26,7 +26,7 @@ public class HsCoopAssetTranslations implements RetroactiveTranslator {
         // and in this case it's just one
         return ERROR_400_PREFIX + messageTranslator.translate(message.substring(ERROR_400_PREFIX.length()));
 
-        // HOWTO extract variable parts from a messages which got created without i18n support:
+        // HOWTO extract variable parts from messages which got created without i18n support:
         //  final var regex = "(?<propertyName>[^ ]+) (?<propertyValue>.+) not found";
         //  final var pattern = Pattern.compile(regex);
         //  final var matcher = pattern.matcher(message);
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionController.java b/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionController.java
index fc273f75..60eba51e 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionController.java
@@ -141,7 +141,8 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
             final ArrayList<String> violations) {
         if (List.of(DEPOSIT, HsOfficeCoopAssetsTransactionTypeResource.ADOPTION).contains(requestBody.getTransactionType())
                 && requestBody.getAssetValue().signum() < 0) {
-            violations.add(messageTranslator.translate("for transactionType={0}, assetValue must be positive but is {1,number,#0.00}",
+            violations.add(messageTranslator.translate(
+                    "office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-positive-but-is-{1,number,#0.00}",
                     requestBody.getTransactionType(), requestBody.getAssetValue()));
         }
     }
@@ -152,7 +153,8 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
         if (List.of(DISBURSAL, HsOfficeCoopAssetsTransactionTypeResource.TRANSFER, CLEARING, LOSS)
                 .contains(requestBody.getTransactionType())
                 && requestBody.getAssetValue().signum() > 0) {
-            violations.add(messageTranslator.translate("for transactionType={0}, assetValue must be negative but is {1,number,#0.00}",
+            violations.add(messageTranslator.translate(
+                    "office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-negative-but-is-{1,number,#0.00}",
                     requestBody.getTransactionType(), requestBody.getAssetValue()));
         }
     }
@@ -161,7 +163,7 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
             final HsOfficeCoopAssetsTransactionInsertResource requestBody,
             final ArrayList<String> violations) {
         if (requestBody.getAssetValue().signum() == 0) {
-            violations.add(messageTranslator.translate("assetValue must not be 0"));
+            violations.add(messageTranslator.translate("office.coop-assets.assetvalue-must-not-be-0"));
         }
     }
 
@@ -227,18 +229,18 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
                     resource.getMembershipUuid()))
                     .orElseThrow(() -> new EntityNotFoundException(
                             messageTranslator.translate(
-                                "{0} \"{1}\" not found", "membership.uuid", resource.getMembershipUuid())));
+                                    "general.{0}-{1}-not-found", "membership.uuid", resource.getMembershipUuid())));
             entity.setMembership(membership);
         }
 
         if (entity.getTransactionType() == REVERSAL) {
             if (resource.getRevertedAssetTxUuid() == null) {
                 throw new ValidationException(messageTranslator.translate(
-                        "a REVERSAL asset transaction requires specifying a revertedAssetTx.uuid"));
+                        "office.coop-assets.a-reversal-asset-transaction-requires-specifying-a-revertedassettx-uuid"));
             }
             final var revertedAssetTx = coopAssetsTransactionRepo.findByUuid(resource.getRevertedAssetTxUuid())
                     .orElseThrow(() -> new EntityNotFoundException(messageTranslator.translate(
-                            "{0} \"{1}\" not found",
+                            "general.{0}-{1}-not-found",
                             "revertedAssetTx.uuid",
                             resource.getRevertedAssetTxUuid())));
             revertedAssetTx.setReversalAssetTx(entity);
@@ -246,7 +248,7 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
             if (resource.getAssetValue().negate().compareTo(revertedAssetTx.getAssetValue()) != 0) {
                 throw new ValidationException(
                         messageTranslator.translate(
-                                "given assetValue {0,number,#0.00} must be the negative value of the reverted asset transaction: {1,number,#0.00}",
+                                "office.coop-assets.given-assetvalue-{0,number,#0.00}-must-be-the-negative-value-of-the-reverted-asset-transaction-{1,number,#0.00}",
                                 resource.getAssetValue(), revertedAssetTx.getAssetValue()));
             }
 
@@ -270,7 +272,7 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
             final var adoptingMembership = determineAdoptingMembership(resource);
             if ( entity.getMembership() == adoptingMembership) {
                 throw new ValidationException(messageTranslator.translate(
-                        "transferring and adopting membership must be different, but both are {0}",
+                        "office.coop-assets.transferring-and-adopting-membership-must-be-different-but-both-are-{0}",
                         adoptingMembership.getTaggedMemberNumber()));
             }
             final var adoptingAssetTx = createAdoptingAssetTx(entity, adoptingMembership);
@@ -285,8 +287,8 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
             // @formatter:off
             final var message =  messageTranslator.translate(
                     resource.getTransactionType() == HsOfficeCoopAssetsTransactionTypeResource.TRANSFER
-                            ? "either {0} or {1} must be given, not both"
-                            : "neither {0} nor {1} must be given for transactionType={2}",
+                            ? "office.coop-assets.either-{0}-or-{1}-must-be-given-not-both"
+                            : "office.coop-assets.neither-{0}-nor-{1}-must-be-given-for-transactiontype-{2}",
                             "adoptingMembership.uuid",
                             "adoptingMembership.memberNumber",
                             resource.getTransactionType());
@@ -298,7 +300,7 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
             final var adoptingMembership = membershipRepo.findByUuid(adoptingMembershipUuid);
             return adoptingMembership.orElseThrow(() ->
                     new ValidationException(messageTranslator.translate(
-                            "{0} \"{1}\" not found or not accessible",
+                            "general.{0}-{1}-not-found-or-not-accessible",
                             "adoptingMembership.uuid",
                             adoptingMembershipUuid)));
         }
@@ -309,14 +311,14 @@ public class HsOfficeCoopAssetsTransactionController implements HsOfficeCoopAsse
             return adoptingMembership.orElseThrow( () ->
                     new ValidationException(
                             messageTranslator.translate(
-                                    "{0} \"{1}\" not found or not accessible",
+                                    "general.{0}-{1}-not-found-or-not-accessible",
                                     "adoptingMembership.memberNumber",
                                     adoptingMembershipMemberNumber)));
         }
 
         throw new ValidationException(
                 messageTranslator.translate(
-                        "either {0} or {1} must be given for transactionType={2}",
+                        "office.coop-assets.either-{0}-or-{1}-must-be-given-for-transactiontype-{2}",
                         "adoptingMembership.uuid",
                         "adoptingMembership.memberNumber",
                         resource.getTransactionType()
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsCoopShareTranslations.java b/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsCoopShareTranslations.java
index 67665441..1353e8d7 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsCoopShareTranslations.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsCoopShareTranslations.java
@@ -16,7 +16,7 @@ public class HsCoopShareTranslations implements RetroactiveTranslator {
 
     @Override
     public boolean canTranslate(final String message) {
-        return message.equals("ERROR: [400] coop shares transaction would result in a negative number of shares");
+        return message.equals("ERROR: [400] office.coop-shares.transaction-would-result-in-a-negative-number-of-shares");
     }
 
     @Override
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsOfficeCoopSharesTransactionController.java b/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsOfficeCoopSharesTransactionController.java
index 5fc1b969..e6ea4850 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsOfficeCoopSharesTransactionController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/coopshares/HsOfficeCoopSharesTransactionController.java
@@ -129,7 +129,8 @@ public class HsOfficeCoopSharesTransactionController implements HsOfficeCoopShar
             final ArrayList<String> violations) {
         if (requestBody.getTransactionType() == SUBSCRIPTION
                 && requestBody.getShareCount() < 0) {
-            violations.add(messageTranslator.translate("for transactionType={0}, shareCount must be positive but is {1}",
+            violations.add(messageTranslator.translate(
+                    "office.coop-shares.for-transactiontype-{0}-sharecount-must-be-positive-but-is-{1}",
                     requestBody.getTransactionType(), requestBody.getShareCount()));
         }
     }
@@ -139,7 +140,8 @@ public class HsOfficeCoopSharesTransactionController implements HsOfficeCoopShar
             final ArrayList<String> violations) {
         if (requestBody.getTransactionType() == CANCELLATION
                 && requestBody.getShareCount() > 0) {
-            violations.add(messageTranslator.translate("for transactionType={0}, shareCount must be negative but is {1}",
+            violations.add(messageTranslator.translate(
+                    "office.coop-shares.for-transactiontype-{0}-sharecount-must-be-negative-but-is-{1}",
                     requestBody.getTransactionType(), requestBody.getShareCount()));
         }
     }
@@ -148,7 +150,7 @@ public class HsOfficeCoopSharesTransactionController implements HsOfficeCoopShar
             final HsOfficeCoopSharesTransactionInsertResource requestBody,
             final ArrayList<String> violations) {
         if (requestBody.getShareCount() == 0) {
-            violations.add(messageTranslator.translate("shareCount must not be 0"));
+            violations.add(messageTranslator.translate("office.coop-shares.sharecount-must-not-be-0"));
         }
     }
 
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonController.java b/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonController.java
index b59d6b1d..7cf10186 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonController.java
@@ -42,7 +42,7 @@ public class HsOfficePersonController implements HsOfficePersonsApi {
         context.assumeRoles(assumedRoles);
 
         final var entities = representedByPersonUuid != null
-            ? personRepo.findPersonsrepresentedByPersonWithUuid(representedByPersonUuid)
+            ? personRepo.findPersonsRepresentedByPersonWithUuid(representedByPersonUuid)
             : personRepo.findPersonByOptionalNameLike(name);
 
         final var resources = mapper.mapList(entities, HsOfficePersonResource.class);
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepository.java b/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepository.java
index e171feef..123d1c04 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepository.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepository.java
@@ -37,7 +37,7 @@ public interface HsOfficePersonRbacRepository extends Repository<HsOfficePersonR
                         OR person.uuid = :personUuid
             """, nativeQuery = true)
     @Timed("app.office.persons.repo.findRepresentedPersons.rbac")
-    List<HsOfficePersonRbacEntity> findPersonsrepresentedByPersonWithUuid(UUID personUuid);
+    List<HsOfficePersonRbacEntity> findPersonsRepresentedByPersonWithUuid(UUID personUuid);
 
     @Timed("app.office.persons.repo.save.rbac")
     HsOfficePersonRbacEntity save(final HsOfficePersonRbacEntity entity);
diff --git a/src/main/java/net/hostsharing/hsadminng/ping/PingController.java b/src/main/java/net/hostsharing/hsadminng/ping/PingController.java
index 668defba..eb39e2cd 100644
--- a/src/main/java/net/hostsharing/hsadminng/ping/PingController.java
+++ b/src/main/java/net/hostsharing/hsadminng/ping/PingController.java
@@ -21,9 +21,8 @@ public class PingController implements TestApi {
     @PreAuthorize("permitAll()")
     @Timed("app.api.ping")
     public ResponseEntity<String> ping() {
-        final var userName = SecurityContextHolder.getContext().getAuthentication().getName();
         // HOWTO translate text with placeholders - also see in resource files i18n/messages_*.properties.
-        final var translatedMessage = messageTranslator.translate("pong {0} - in English", userName);
+        final var translatedMessage = messageTranslator.translate("test.pinged--in-your-language");
         return ResponseEntity.ok(translatedMessage + "\n");
     }
 
diff --git a/src/main/resources/application.yml b/src/main/resources/application.yml
index 520d897f..269119c9 100644
--- a/src/main/resources/application.yml
+++ b/src/main/resources/application.yml
@@ -72,9 +72,9 @@ metrics:
 logging:
     level:
         org.springframework.security: info
-        org.springframework.web: DEBUG
-        org.springframework.web.method.annotation: DEBUG
-        org.springframework.validation: DEBUG
+#        org.springframework.web: DEBUG
+#        org.springframework.web.method.annotation: DEBUG
+#        org.springframework.validation: DEBUG
 # HOWTO configure logging, e.g. logging to a separate file, see:
 #   https://docs.spring.io/spring-boot/reference/features/logging.html
 
diff --git a/src/main/resources/db/changelog/5-hs-office/511-coopshares/5110-hs-office-coopshares.sql b/src/main/resources/db/changelog/5-hs-office/511-coopshares/5110-hs-office-coopshares.sql
index c6327e7b..be567a3c 100644
--- a/src/main/resources/db/changelog/5-hs-office/511-coopshares/5110-hs-office-coopshares.sql
+++ b/src/main/resources/db/changelog/5-hs-office/511-coopshares/5110-hs-office-coopshares.sql
@@ -33,7 +33,7 @@ alter table hs_office.coopsharetx
 --//
 
 -- ============================================================================
---changeset marc.sandlus:hs-office-coopshares-SHARE-COUNT-CONSTRAINT-BY-TRIGGER endDelimiter:--//
+--changeset marc.sandlus:hs-office-coopshares-SHARE-COUNT-CONSTRAINT-BY-TRIGGER runOnChange:true validCheckSum:ANY endDelimiter:--//
 -- ----------------------------------------------------------------------------
 
 alter table hs_office.coopsharetx drop constraint if exists check_positive_total_shares_count;
@@ -42,7 +42,6 @@ drop function if exists hs_office.coopsharestx_check_positive_total cascade;
 
 create or replace function hs_office.coopsharetx_enforce_positive_total()
 returns trigger as $$
-
 declare
     currentShareCount integer;
     totalShareCount integer;
@@ -53,12 +52,13 @@ begin
     into currentShareCount;
     totalShareCount := currentShareCount + NEW.shareCount;
     if totalShareCount < 0 then
-        raise exception '[400] coop shares transaction would result in a negative number of shares';
+        raise exception '[400] office.coop-shares.transaction-would-result-in-a-negative-number-of-shares';
     end if;
     return NEW;
 end;
 $$ LANGUAGE plpgsql;;
 
+drop trigger if exists positive_total_shares_count_tg on hs_office.coopsharetx;
 
 create trigger positive_total_shares_count_tg before insert
     on hs_office.coopsharetx
diff --git a/src/main/resources/db/changelog/5-hs-office/512-coopassets/5120-hs-office-coopassets.sql b/src/main/resources/db/changelog/5-hs-office/512-coopassets/5120-hs-office-coopassets.sql
index 90d1c37b..0a53f2a2 100644
--- a/src/main/resources/db/changelog/5-hs-office/512-coopassets/5120-hs-office-coopassets.sql
+++ b/src/main/resources/db/changelog/5-hs-office/512-coopassets/5120-hs-office-coopassets.sql
@@ -73,7 +73,7 @@ CREATE TRIGGER enforce_transaction_constraints
 --//
 
 -- ============================================================================
---changeset marc.sandlus:hs-office-coopassets-ASSET-VALUE-CONSTRAINT-BY-TRIGGER endDelimiter:--//
+--changeset marc.sandlus:hs-office-coopassets-ASSET-VALUE-CONSTRAINT-BY-TRIGGER runOnChange:true validCheckSum:ANY endDelimiter:--//
 -- ----------------------------------------------------------------------------
 
 alter table hs_office.coopassettx
@@ -83,7 +83,6 @@ drop function if exists hs_office.coopassetstx_check_positive_total cascade;
 
 create or replace function hs_office.coopassettx_enforce_positive_total()
 returns trigger as $$
-
 declare
     currentAssetValue numeric(12,2);
     totalAssetValue numeric(12,2);
@@ -94,12 +93,14 @@ begin
         into currentAssetValue;
     totalAssetValue := currentAssetValue + NEW.assetValue;
     if totalAssetValue::numeric < 0 then
-        raise exception '[400] coop assets transaction would result in a negative balance of assets';
+        raise exception '[400] office.coop-assets.transaction-would-result-in-a-negative-balance-of-assets';
     end if;
     return NEW;
 end;
 $$ LANGUAGE plpgsql;;
 
+drop trigger if exists positive_total_assets_count_tg on hs_office.coopassettx;
+
 create trigger positive_total_assets_count_tg before insert
     on hs_office.coopassettx
     for each row execute function hs_office.coopassettx_enforce_positive_total();
diff --git a/src/main/resources/i18n/messages_de.properties b/src/main/resources/i18n/messages_de.properties
index c5e7bcf5..5c1863ed 100644
--- a/src/main/resources/i18n/messages_de.properties
+++ b/src/main/resources/i18n/messages_de.properties
@@ -1,36 +1,38 @@
 # This file must be in UTF-8 encoding. Check if you see umlauts or garbage: äöüÄÖÜß.
 # HINT IntelliJ IDEA shows unused keys in gray.
 
-pong\ {0}\ -\ in\ English=pong {0} - auf Deutsch
+test.pinged--in-your-language=pinged - auf Deutsch
+test.ponged-{0}--in-your-language=ponged {0} - auf Deutsch
+test.available-in-all-properties-files=Hallo {0} - DE!
 
-# config (including authorization)
-CAS\ service-ticket\ could\ not\ be\ verified=CAS Service-Ticket konnte nicht verifiziert werden
-unknown\ authorization\ ticket=unbekanntes Autorisierungs-Ticket
+# authorization
+auth.cas-service-ticket-could-not-be-verified=CAS Service-Ticket konnte nicht verifiziert werden
+auth.unknown-authorization-ticket=unbekanntes Autorisierungs-Ticket
 
 # general validations
-{0}\ "{1}"\ not\ found={0} "{1}" nicht gefunden
-{0}\ "{1}"\ not\ found\ or\ not\ accessible={0} "{1}" nicht gefunden oder nicht zugänglich
-but\ is=ist aber
+general.{0}-{1}-not-found={0} "{1}" nicht gefunden
+general.{0}-{1}-not-found-or-not-accessible={0} "{1}" nicht gefunden oder nicht zugänglich
+general.but-is=ist aber
 
 # credentials validations
-existing\ {0}\ does\ not\ match\ given\ resource\ {1}=existierender Credentials-Context {0} passt nicht zum angegebenen {1}
-access-denied-personUuid-{0}-not-represented-by-currently-logged-in-person=Zugriff verweigert: personUuid "{0}" wird von der eingeloggten Person nicht repräsentiert
+credentials.existing-{0}-does-not-match-given-resource-{1}=existierender Credentials-Context {0} passt nicht zum angegebenen {1}
+credentials.access-denied-person-uuid-{0}-not-represented-by-currently-logged-in-person=Zugriff verweigert: personUuid "{0}" wird von der eingeloggten Person nicht repräsentiert
 
 # office.coop-shares
-for\ transactionType\={0},\ shareCount\ must\ be\ positive\ but\ is\ {1}=für transactionType={0}, muss shareCount positiv sein, ist aber {1}
-for\ transactionType\={0},\ shareCount\ must\ be\ negative\ but\ is\ {1}=für transactionType={0}, muss shareCount negativ sein, ist aber {1}
-shareCount\ must\ not\ be\ 0=shareCount darf nicht 0 sein
-coop\ shares\ transaction\ would\ result\ in\ a\ negative\ number\ of\ shares=Geschäftsanteile-Transaktion würde zu negativen Geschäftsanteilen führen
+office.coop-shares.for-transactiontype-{0}-sharecount-must-be-positive-but-is-{1}=für transactionType={0}, muss shareCount positiv sein, ist aber {1}
+office.coop-shares.for-transactiontype-{0}-sharecount-must-be-negative-but-is-{1}=für transactionType={0}, muss shareCount negativ sein, ist aber {1}
+office.coop-shares.sharecount-must-not-be-0=shareCount darf nicht 0 sein
+office.coop-shares.transaction-would-result-in-a-negative-number-of-shares=Geschäftsanteile-Transaktion würde zu negativen Geschäftsanteilen führen
 
 # office.coop-assets
-either\ {0}\ or\ {1}\ must\ be\ given=entweder {0} oder {1} muss angegeben werden
-either\ {0}\ or\ {1}\ must\ be\ given,\ not\ both=entweder {0} oder {1} muss angegeben werden, nicht beide
-either\ {0}\ or\ {1}\ must\ be\ given\ for\ transactionType\={2}=für transactionType={2} muss entweder {0} oder {1} angegeben werden
-neither\ {0}\ nor\ {1}\ must\ be\ given\ for\ transactionType\={2}=für transactionType={2} darf weder {0} noch {1} angegeben werden
-assetValue\ must\ not\ be\ 0=assetValue darf nicht 0 sein
-for\ transactionType\={0},\ assetValue\ must\ be\ positive\ but\ is\ {1,number,#0.00}=für transactionType={0}, muss assetValue positiv sein, ist aber {1,number,#0.00}
-for\ transactionType\={0},\ assetValue\ must\ be\ negative\ but\ is\ {1,number,#0.00}=für transactionType={0}, muss assetValue negativ sein, ist aber {1,number,#0.00}
-given\ assetValue\ {0,number,#0.00}\ must\ be\ the\ negative\ value\ of\ the\ reverted\ asset\ transaction\:\ {1,number,#0.00}=assetValue={0,number,#0.00} muss dem negativen Wert des Wertes der stornierten Geschäftsguthaben-Transaktion entsprechen: {1,number,#0.00}
-a\ REVERSAL\ asset\ transaction\ requires\ specifying\ a\ revertedAssetTx.uuid=eine REVERSAL Geschäftsguthaben-Transaktion erfordert die Angabe einer revertedAssetTx.uuid
-transferring\ and\ adopting\ membership\ must\ be\ different,\ but\ both\ are\ {0}=übertragende und annehmende Mitgliedschaft müssen unterschiedlich sein, aber beide sind {0}
-coop\ assets\ transaction\ would\ result\ in\ a\ negative\ balance\ of\ assets=Geschäftsguthaben-Transaktion würde zu einem negativen Geschäftsguthaben-Saldo führen
+office.coop-assets.either-{0}-or-{1}-must-be-given=entweder {0} oder {1} muss angegeben werden
+office.coop-assets.either-{0}-or-{1}-must-be-given-not-both=entweder {0} oder {1} muss angegeben werden, nicht beide
+office.coop-assets.either-{0}-or-{1}-must-be-given-for-transactiontype-{2}=für transactionType={2} muss entweder {0} oder {1} angegeben werden
+office.coop-assets.neither-{0}-nor-{1}-must-be-given-for-transactiontype-{2}=für transactionType={2} darf weder {0} noch {1} angegeben werden
+office.coop-assets.assetvalue-must-not-be-0=assetValue darf nicht 0 sein
+office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-positive-but-is-{1,number,#0.00}=für transactionType={0}, muss assetValue positiv sein, ist aber {1,number,#0.00}
+office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-negative-but-is-{1,number,#0.00}=für transactionType={0}, muss assetValue negativ sein, ist aber {1,number,#0.00}
+office.coop-assets.given-assetvalue-{0,number,#0.00}-must-be-the-negative-value-of-the-reverted-asset-transaction-{1,number,#0.00}=assetValue={0,number,#0.00} muss dem negativen Wert des Wertes der stornierten Geschäftsguthaben-Transaktion entsprechen: {1,number,#0.00}
+office.coop-assets.a-reversal-asset-transaction-requires-specifying-a-revertedassettx-uuid=eine REVERSAL Geschäftsguthaben-Transaktion erfordert die Angabe einer revertedAssetTx.uuid
+office.coop-assets.transferring-and-adopting-membership-must-be-different-but-both-are-{0}=übertragende und annehmende Mitgliedschaft müssen unterschiedlich sein, aber beide sind {0}
+office.coop-assets.transaction-would-result-in-a-negative-balance-of-assets=Geschäftsguthaben-Transaktion würde zu einem negativen Geschäftsguthaben-Saldo führen
diff --git a/src/main/resources/i18n/messages_en.properties b/src/main/resources/i18n/messages_en.properties
index e318f0be..95981898 100644
--- a/src/main/resources/i18n/messages_en.properties
+++ b/src/main/resources/i18n/messages_en.properties
@@ -1,9 +1,39 @@
 # This file must be in UTF-8 encoding. Check if you see umlauts or garbage: äöüÄÖÜß
 # HINT IntelliJ IDEA shows unused keys in gray.
 
-# If the English translation is identical to the translation-key, it does not need to be included here.
-# But in that case, you can NOT use a prefix - or the prefix would be shown to the user as well.
-# I'm not sure, though, if using the english default translations as keys is really a good idea.
+test.pinged--in-your-language=pinged - in English
+test.ponged-{0}--in-your-language=ponged {0} - in English
+test.available-in-all-properties-files=Hello {0} - EN!
+
+# authorization
+auth.cas-service-ticket-could-not-be-verified=CAS service-ticket could not be verified
+auth.unknown-authorization-ticket=unknown authorization ticket
+
+# general validations
+general.{0}-{1}-not-found={0} "{1}" not found
+general.{0}-{1}-not-found-or-not-accessible={0} "{1}" not found or not accessible
+general.but-is=but is
 
 # credentials validations
-access-denied-personUuid-{0}-not-represented-by-currently-logged-in-person=access denied: personUuid "{0}" not represented by currently logged in person
+credentials.existing-{0}-does-not-match-given-resource-{1}=existing {0} does not match given resource {1}
+credentials.access-denied-person-uuid-{0}-not-represented-by-currently-logged-in-person=access denied: personUuid "{0}" not represented by currently logged in person
+
+# office.coop-shares
+office.coop-shares.for-transactiontype-{0}-sharecount-must-be-positive-but-is-{1}=for transactiontType {0} shareCount must be positive but is {1}
+office.coop-shares.for-transactiontype-{0}-sharecount-must-be-negative-but-is-{1}=for transactiontType {0} shareCount must be negative but is {1}
+office.coop-shares.sharecount-must-not-be-0=shareCount must not be 0
+office.coop-shares.transaction-would-result-in-a-negative-number-of-shares=coop shares transaction would result in a negative number of shares
+
+# office.coop-assets
+office.coop-assets.either-{0}-or-{1}-must-be-given=either {0} or {1} must be given
+office.coop-assets.either-{0}-or-{1}-must-be-given-not-both=either {0} or {1} must be given not both
+office.coop-assets.either-{0}-or-{1}-must-be-given-for-transactiontype-{2}=either {0} or {1} must be given for transactionType {2}
+office.coop-assets.neither-{0}-nor-{1}-must-be-given-for-transactiontype-{2}=neither {0} nor {1} must be given for transactionType {2}
+office.coop-assets.assetvalue-must-not-be-0=assetvalue must not be 0
+office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-positive-but-is-{1,number,#0.00}=for transactionType {0} assetValue must be positive but is {1,number,#0.00}
+office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-negative-but-is-{1,number,#0.00}=for transactionType {0} assetValue must be negative but is {1,number,#0.00}
+office.coop-assets.given-assetvalue-{0,number,#0.00}-must-be-the-negative-value-of-the-reverted-asset-transaction-{1,number,#0.00}=given assetValue {0,number,#0.00} must be the negative value of the reverted asset transaction {1,number,#0.00}
+office.coop-assets.a-reversal-asset-transaction-requires-specifying-a-revertedassettx-uuid=a reversal asset transaction requires specifying a revertedAssetTx uuid
+office.coop-assets.transferring-and-adopting-membership-must-be-different-but-both-are-{0}=transferring and adopting membership must be different but both are {0}
+office.coop-assets.transaction-would-result-in-a-negative-balance-of-assets=coop assets transaction would result in a negative balance of assets
+
diff --git a/src/main/resources/i18n/messages_fr.properties b/src/main/resources/i18n/messages_fr.properties
new file mode 100644
index 00000000..9ac7fa5f
--- /dev/null
+++ b/src/main/resources/i18n/messages_fr.properties
@@ -0,0 +1,38 @@
+# This file must be in UTF-8 encoding. Check if you see umlauts or garbage: äöüÄÖÜß
+# HINT IntelliJ IDEA shows unused keys in gray.
+
+# test.ponged--in-your-language=this translation is deliberately missing
+test.pinged--in-your-language=ponged {0} - en Francais
+test.available-in-all-properties-files=Salut {0} - FR!
+
+# authorization
+auth.cas-service-ticket-could-not-be-verified=Le ticket de service CAS n'a pas pu être vérifié
+auth.unknown-authorization-ticket=ticket d'autorisation inconnu
+
+# general validations
+general.{0}-{1}-not-found={0} "{1}" non trouvé
+general.{0}-{1}-not-found-or-not-accessible={0} "{1}" non trouvé ou non accessible
+general.but-is=mais c'est
+
+# credentials validations
+credentials.existing-{0}-does-not-match-given-resource-{1}={0} existant ne correspond pas à la ressource donnée {1}
+credentials.access-denied-person-uuid-{0}-not-represented-by-currently-logged-in-person=accès refusé : personUuid "{0}" non représenté par la personne actuellement connectée
+
+# office.coop-shares
+office.coop-shares.for-transactiontype-{0}-sharecount-must-be-positive-but-is-{1}=pour le type de transaction {0}, shareCount doit être positif mais est {1}
+office.coop-shares.for-transactiontype-{0}-sharecount-must-be-negative-but-is-{1}=pour le type de transaction {0}, shareCount doit être négatif mais est {1}
+office.coop-shares.sharecount-must-not-be-0=shareCount ne doit pas être 0
+office.coop-shares.transaction-would-result-in-a-negative-number-of-shares=la transaction de parts coopératives résulterait en un nombre négatif de parts
+
+# office.coop-assets
+office.coop-assets.either-{0}-or-{1}-must-be-given=soit {0} soit {1} doit être fourni
+office.coop-assets.either-{0}-or-{1}-must-be-given-not-both=soit {0} soit {1} doit être fourni, pas les deux
+office.coop-assets.either-{0}-or-{1}-must-be-given-for-transactiontype-{2}=soit {0} soit {1} doit être fourni pour le type de transaction {2}
+office.coop-assets.neither-{0}-nor-{1}-must-be-given-for-transactiontype-{2}=ni {0} ni {1} ne doit être fourni pour le type de transaction {2}
+office.coop-assets.assetvalue-must-not-be-0=assetvalue ne doit pas être 0
+office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-positive-but-is-{1,number,#0.00}=pour le type de transaction {0}, assetValue doit être positif mais est {1,number,#0.00}
+office.coop-assets.for-transactiontype-{0}-assetvalue-must-be-negative-but-is-{1,number,#0.00}=pour le type de transaction {0}, assetValue doit être négatif mais est {1,number,#0.00}
+office.coop-assets.given-assetvalue-{0,number,#0.00}-must-be-the-negative-value-of-the-reverted-asset-transaction-{1,number,#0.00}=assetValue donné {0,number,#0.00} doit être la valeur négative de la transaction d'actif annulée {1,number,#0.00}
+office.coop-assets.a-reversal-asset-transaction-requires-specifying-a-revertedassettx-uuid=une transaction d'actif d'annulation nécessite de spécifier un uuid revertedAssetTx
+office.coop-assets.transferring-and-adopting-membership-must-be-different-but-both-are-{0}=l'adhésion transférant et adoptante doit être différente, mais les deux sont {0}
+office.coop-assets.transaction-would-result-in-a-negative-balance-of-assets=la transaction d'actifs coopératifs résulterait en un solde négatif d'actifs
diff --git a/src/test/java/net/hostsharing/hsadminng/config/CasAuthenticationFilterIntegrationTest.java b/src/test/java/net/hostsharing/hsadminng/config/CasAuthenticationFilterIntegrationTest.java
index 3e00b7c3..db5b7e00 100644
--- a/src/test/java/net/hostsharing/hsadminng/config/CasAuthenticationFilterIntegrationTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/config/CasAuthenticationFilterIntegrationTest.java
@@ -69,7 +69,7 @@ class CasAuthenticationFilterIntegrationTest {
 
         // when
         final var result = restTemplate.exchange(
-                "http://localhost:" + this.serverPort + "/api/ping",
+                "http://localhost:" + this.serverPort + "/api/pong",
                 HttpMethod.GET,
                 new HttpEntity<>(null, headers(entry("Authorization", "ST-valid"))),
                 String.class
@@ -77,7 +77,7 @@ class CasAuthenticationFilterIntegrationTest {
 
         // then
         assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
-        assertThat(result.getBody()).startsWith("pong " + username);
+        assertThat(result.getBody()).startsWith("ponged " + username);
         // HOWTO assert log messages
         assertThat(capturedOutput.getOut()).containsPattern(
                 LogbackLogPattern.of(LogLevel.DEBUG, RealCasAuthenticator.class, "CAS-user: " + username));
diff --git a/src/test/java/net/hostsharing/hsadminng/config/MessageTranslatorUnitTest.java b/src/test/java/net/hostsharing/hsadminng/config/MessageTranslatorUnitTest.java
new file mode 100644
index 00000000..b77fde1e
--- /dev/null
+++ b/src/test/java/net/hostsharing/hsadminng/config/MessageTranslatorUnitTest.java
@@ -0,0 +1,72 @@
+package net.hostsharing.hsadminng.config;
+
+import lombok.AllArgsConstructor;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.web.context.WebApplicationContext;
+
+import net.hostsharing.hsadminng.context.Context;
+
+import java.util.Locale;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import lombok.val;
+
+@SpringBootTest(classes = {
+        MessagesResourceConfig.class,
+        MessageTranslator.class
+})
+@ActiveProfiles("test")
+@Tag("generalIntegrationTest")
+class MessageTranslatorIntegrationTest {
+
+    @Autowired
+    private WebApplicationContext webApplicationContext;
+
+    @MockitoBean
+    private Context contextMock; // avoiding dependency issues
+
+    @AllArgsConstructor
+    enum TestCases {
+        ENGLISH_KNOWN(Locale.ENGLISH, "test.ponged-{0}--in-your-language",
+                "ponged testUser - in English"),
+        ENGLISH_UNKNOWN(Locale.ENGLISH, "test.ponged-{0}--unknown-key",
+                "【⍰ponged testUser - unknown key⍰】"),
+        ENGLISH_US(Locale.of("en", "US"), "test.ponged-{0}--in-your-language",
+                "ponged testUser - in English"),
+        ENGLISH_UK(Locale.of("en", "UK"), "test.ponged-{0}--in-your-language",
+                "ponged testUser - in English"),
+        GERMAN_KNOWN(Locale.GERMAN, "test.ponged-{0}--in-your-language",
+                "ponged testUser - auf Deutsch"),
+        FRENCH_UNKNOWN_BUT_ENGLISH_KNOWN(Locale.FRENCH, "test.ponged-{0}--in-your-language",
+                "【⍰ponged testUser - in English⍰】"),
+        FRENCH_UNKNOWN_AND_ENGLISH_UNKNOWN(Locale.FRENCH, "test.ponged-{0}--unknown-key",
+                "【⍰ponged testUser - unknown key⍰】"),
+        UNKNOWN_LOCALE_AND_ENGLISH_KNOWN(Locale.TRADITIONAL_CHINESE,
+                "test.ponged-{0}--in-your-language", "【⍰ponged testUser - in English⍰】"),
+        UNKNOWN_LOCALE_AND_ENGLISH_UNKNOWN(Locale.TRADITIONAL_CHINESE, "test.ponged-{0}--unknown-key",
+                "【⍰ponged testUser - unknown key⍰】");
+        final Locale locale;
+        final String messageKey;
+        final String expectedTranslation;
+    }
+
+    @ParameterizedTest
+    @EnumSource(TestCases.class)
+    void shouldHandleDifferentLocalesAppropriately(final TestCases testCase) {
+        // given
+        val messageTranslator = webApplicationContext.getBean(MessageTranslator.class);
+
+        // when
+        val result = messageTranslator.translateTo(testCase.locale, testCase.messageKey, "testUser");
+
+        // then
+        assertThat(result).isEqualTo(testCase.expectedTranslation);
+    }
+}
diff --git a/src/test/java/net/hostsharing/hsadminng/config/WebSecurityConfigIntegrationTest.java b/src/test/java/net/hostsharing/hsadminng/config/WebSecurityConfigIntegrationTest.java
index 0210c00e..bbff1b20 100644
--- a/src/test/java/net/hostsharing/hsadminng/config/WebSecurityConfigIntegrationTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/config/WebSecurityConfigIntegrationTest.java
@@ -67,14 +67,14 @@ class WebSecurityConfigIntegrationTest {
 
         // http request
         final var result = restTemplate.exchange(
-                "http://localhost:" + this.serverPort + "/api/ping",
+                "http://localhost:" + this.serverPort + "/api/pong",
                 HttpMethod.GET,
                 httpHeaders(entry("Authorization", "Bearer ST-fake-cas-ticket")),
                 String.class
         );
 
         assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
-        assertThat(result.getBody()).startsWith("pong fake-user-name");
+        assertThat(result.getBody()).startsWith("ponged fake-user-name");
     }
 
     @Test
@@ -85,18 +85,18 @@ class WebSecurityConfigIntegrationTest {
 
         // http request
         final var result = restTemplate.exchange(
-                "http://localhost:" + this.serverPort + "/api/ping",
+                "http://localhost:" + this.serverPort + "/api/pong",
                 HttpMethod.GET,
                 httpHeaders(entry("Authorization", "Bearer TGT-fake-cas-ticket")),
                 String.class
         );
 
         assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
-        assertThat(result.getBody()).startsWith("pong fake-user-name");
+        assertThat(result.getBody()).startsWith("ponged fake-user-name");
     }
 
     @Test
-    void accessToApiWithInvalidTicketGrantingTicketShouldBePermitted() {
+    void accessToOpenApiWithInvalidTicketGrantingTicketShouldBePermitted() {
         // given
         givenCasServiceTicketForTicketGrantingTicket("TGT-fake-cas-ticket", "ST-fake-cas-ticket");
         givenCasTicketValidationResponse("ST-fake-cas-ticket", "fake-user-name");
@@ -113,14 +113,14 @@ class WebSecurityConfigIntegrationTest {
     }
 
     @Test
-    void accessToPingApiWithoutTokenShouldBePermitted() {
+    void accessToOpenApiWithoutTokenShouldBePermitted() {
         final var result = this.restTemplate.getForEntity(
                 "http://localhost:" + this.serverPort + "/api/ping", String.class);
         assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
     }
 
     @Test
-    void accessToPongApiWithValidTokenShouldBePermitted() {
+    void accessToProtectedApiWithValidTokenShouldBePermitted() {
         // given
         givenCasTicketValidationResponse("ST-fake-cas-ticket", "fake-user-name");
 
@@ -137,7 +137,7 @@ class WebSecurityConfigIntegrationTest {
     }
 
     @Test
-    void accessToPongApiWithInvalidTokenShouldBeDenied() {
+    void accessToProtectedApiWithInvalidTokenShouldBeDenied() {
         // given
         givenCasTicketValidationResponse("ST-fake-cas-ticket", "fake-user-name");
 
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsControllerRestTest.java b/src/test/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsControllerRestTest.java
index 0ef3f4a1..c3c9a409 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsControllerRestTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/accounts/HsCredentialsControllerRestTest.java
@@ -190,7 +190,7 @@ class HsCredentialsControllerRestTest {
         given(rbacPersonRepo.findByUuid(personUuid)).willReturn(Optional.of(
                 HsOfficePersonRbacEntity.builder().uuid(personUuid).personType(NATURAL_PERSON).build()
         ));
-        given(rbacPersonRepo.findPersonsrepresentedByPersonWithUuid(personUuid)).willReturn(List.of(
+        given(rbacPersonRepo.findPersonsRepresentedByPersonWithUuid(personUuid)).willReturn(List.of(
                 // some persons, but not the one from the login-user itself
                 HsOfficePersonRbacEntity.builder().uuid(UUID.randomUUID()).personType(NATURAL_PERSON).build(),
                 HsOfficePersonRbacEntity.builder().uuid(UUID.randomUUID()).personType(LEGAL_PERSON).build()
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionControllerAcceptanceTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionControllerAcceptanceTest.java
index 1c414db8..ce6ef5aa 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionControllerAcceptanceTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/coopassets/HsOfficeCoopAssetsTransactionControllerAcceptanceTest.java
@@ -4,6 +4,7 @@ import io.restassured.RestAssured;
 import io.restassured.http.ContentType;
 import net.hostsharing.hsadminng.HsadminNgApplication;
 import net.hostsharing.hsadminng.config.MessageTranslator;
+import net.hostsharing.hsadminng.config.MessagesResourceConfig;
 import net.hostsharing.hsadminng.context.Context;
 import net.hostsharing.hsadminng.hs.office.membership.HsOfficeMembershipRepository;
 import net.hostsharing.hsadminng.rbac.test.ContextBasedTestWithCleanup;
@@ -36,7 +37,7 @@ import static org.hamcrest.Matchers.startsWith;
 @SpringBootTest(
         webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
         classes = { HsadminNgApplication.class, DisableSecurityConfig.class, JpaAttempt.class,
-                    MessageTranslator.class}
+                    MessagesResourceConfig.class, MessageTranslator.class}
 )
 @ActiveProfiles("test")
 @Transactional
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/membership/HsOfficeMembershipControllerRestTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/membership/HsOfficeMembershipControllerRestTest.java
index 7914dacd..b91f2ae9 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/membership/HsOfficeMembershipControllerRestTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/membership/HsOfficeMembershipControllerRestTest.java
@@ -2,6 +2,7 @@ package net.hostsharing.hsadminng.hs.office.membership;
 
 import io.hypersistence.utils.hibernate.type.range.Range;
 import net.hostsharing.hsadminng.config.MessageTranslator;
+import net.hostsharing.hsadminng.config.MessagesResourceConfig;
 import net.hostsharing.hsadminng.context.Context;
 import net.hostsharing.hsadminng.hs.office.coopassets.HsOfficeCoopAssetsTransactionRepository;
 import net.hostsharing.hsadminng.hs.office.partner.HsOfficePartnerRbacEntity;
@@ -41,7 +42,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 @WebMvcTest(HsOfficeMembershipController.class)
-@Import({StrictMapper.class, DisableSecurityConfig.class, MessageTranslator.class})
+@Import({ StrictMapper.class, DisableSecurityConfig.class, MessagesResourceConfig.class, MessageTranslator.class})
 @ActiveProfiles("test")
 public class HsOfficeMembershipControllerRestTest {
 
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepositoryIntegrationTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepositoryIntegrationTest.java
index cb03c6e1..4c88315e 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepositoryIntegrationTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/person/HsOfficePersonRbacRepositoryIntegrationTest.java
@@ -259,14 +259,14 @@ class HsOfficePersonRbacRepositoryIntegrationTest extends ContextBasedTestWithCl
     }
 
     @Test
-    public void findPersonsrepresentedByPersonWithUuid() {
+    public void findPersonsRepresentedByPersonWithUuid() {
 
         // given
         context("superuser-alex@hostsharing.net");
         final var personUuid = personRbacRepo.findPersonByOptionalNameLike("Fouler").getFirst().getUuid();
 
         // when
-        @SuppressWarnings("unchecked") final List<HsOfficePersonRbacEntity> representedPersons = personRbacRepo.findPersonsrepresentedByPersonWithUuid(personUuid);
+        @SuppressWarnings("unchecked") final List<HsOfficePersonRbacEntity> representedPersons = personRbacRepo.findPersonsRepresentedByPersonWithUuid(personUuid);
 
         // then
         assertThat(representedPersons).map(Object::toString).containsExactlyInAnyOrder(
diff --git a/src/test/java/net/hostsharing/hsadminng/ping/PingControllerAcceptanceTest.java b/src/test/java/net/hostsharing/hsadminng/ping/PingControllerAcceptanceTest.java
index df7516bf..32670487 100644
--- a/src/test/java/net/hostsharing/hsadminng/ping/PingControllerAcceptanceTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/ping/PingControllerAcceptanceTest.java
@@ -6,6 +6,7 @@ import net.hostsharing.hsadminng.config.DisableSecurityConfig;
 import net.hostsharing.hsadminng.context.Context;
 import net.hostsharing.hsadminng.rbac.test.JpaAttempt;
 import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.EnumSource;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -40,36 +41,52 @@ class PingControllerAcceptanceTest {
     @Autowired
     Context contextMock;
 
-    enum PingTranslationTestCase {
-        EN(Locale.ENGLISH, "pong superuser-alex@hostsharing.net - in English"),
-        DE(Locale.GERMAN, "pong superuser-alex@hostsharing.net - auf Deutsch"),
-        FR(Locale.FRENCH, "pong superuser-alex@hostsharing.net - in English [fr translation missing]");
+    enum PongTranslationTestCase {
+        EN(Locale.ENGLISH, "ponged superuser-alex@hostsharing.net - in English"),
+        DE(Locale.GERMAN, "ponged superuser-alex@hostsharing.net - auf Deutsch");
 
         Locale givenLocale;
         CharSequence expectedPongTranslation;
 
-        PingTranslationTestCase(final Locale givenLocale, final String expectedPongTranslation) {
+        PongTranslationTestCase(final Locale givenLocale, final String expectedPongTranslation) {
             this.givenLocale = givenLocale;
             this.expectedPongTranslation = expectedPongTranslation;
         }
     }
 
     @ParameterizedTest
-    @EnumSource(PingTranslationTestCase.class)
-    void pingRepliesWithTranslatedPongResponse(final PingTranslationTestCase testCase) {
+    @EnumSource(PongTranslationTestCase.class)
+    void pongRepliesWithTranslatedPongResponse(final PongTranslationTestCase testCase) {
         final var responseBody = RestAssured // @formatter:off
                 .given()
                     .header("Authorization", "Bearer superuser-alex@hostsharing.net")
                     .header("Accept-Language", testCase.givenLocale)
                     .port(port)
                 .when()
-                    .get("http://localhost/api/ping")
+                    .get("http://localhost/api/pong")
                 .then().log().all().assertThat()
                     .statusCode(200)
                     .contentType("text/plain;charset=UTF-8")
                     .extract().body().asString();
-                // @formatter:on
+        // @formatter:on
 
         assertThat(responseBody).isEqualTo(testCase.expectedPongTranslation + "\n");
     }
+
+    @Test
+    void pingRepliesWithTranslatedPongResponse() {
+        final var responseBody = RestAssured // @formatter:off
+                .given()
+                    .header("Accept-Language", Locale.GERMAN)
+                    .port(port)
+                .when()
+                    .get("http://localhost/api/ping")
+                    .then().log().all().assertThat()
+                    .statusCode(200)
+                    .contentType("text/plain;charset=UTF-8")
+                    .extract().body().asString();
+        // @formatter:on
+
+        assertThat(responseBody).isEqualTo("pinged - auf Deutsch\n");
+    }
 }
diff --git a/src/test/java/net/hostsharing/hsadminng/ping/PingControllerRestTest.java b/src/test/java/net/hostsharing/hsadminng/ping/PingControllerRestTest.java
index 3d584838..ac650b00 100644
--- a/src/test/java/net/hostsharing/hsadminng/ping/PingControllerRestTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/ping/PingControllerRestTest.java
@@ -38,8 +38,8 @@ class PingControllerRestTest {
 
     @RequiredArgsConstructor
     enum I18nTestCases {
-        EN("en", "pong anonymousUser - in English"),
-        DE("de", "pong anonymousUser - auf Deutsch");
+        EN("en", "pinged - in English"),
+        DE("de", "pinged - auf Deutsch");
 
         final String language;
         final String expectedTranslation;