diff --git a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/BaseValidator.java b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/BaseValidator.java
index cac38fb49..cc8576f70 100644
--- a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/BaseValidator.java
+++ b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/BaseValidator.java
@@ -146,7 +146,7 @@ public class BaseValidator {
   }
 
     
-  private String formatMessage(String theMessage, Object... theMessageArguments) {
+  protected String formatMessage(String theMessage, Object... theMessageArguments) {
     String message;
     if (theMessageArguments != null && theMessageArguments.length > 0) {
       message = MessageFormat.format(messages.getString(theMessage), theMessageArguments);
diff --git a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java
index 05290ed97..76cb6f88e 100644
--- a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java
+++ b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java
@@ -5224,12 +5224,11 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
   private void validateObservation(List<ValidationMessage> errors, Element element, NodeStack stack) {
     // all observations should have a subject, a performer, and a time
 
-    bpCheck(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), element.getNamedChild("subject") != null, "All observations should have a subject");
+    bpCheck(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), element.getNamedChild("subject") != null, I18nConstants.ALL_OBSERVATIONS_SHOULD_HAVE_A_SUBJECT);
     List<Element> performers = new ArrayList<>();
     element.getNamedChildren("performer", performers);
-    bpCheck(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), performers.size() > 0, "All observations should have a performer");
-    bpCheck(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), element.getNamedChild("effectiveDateTime") != null || element.getNamedChild("effectivePeriod") != null,
-      "All observations should have an effectiveDateTime or an effectivePeriod");
+    bpCheck(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), performers.size() > 0, I18nConstants.ALL_OBSERVATIONS_SHOULD_HAVE_A_PERFORMER);
+    bpCheck(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), element.getNamedChild("effectiveDateTime") != null || element.getNamedChild("effectivePeriod") != null, I18nConstants.ALL_OBSERVATIONS_SHOULD_HAVE_AN_EFFECTIVEDATETIME_OR_AN_EFFECTIVEPERIOD);
   }
 
   /*
diff --git a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/utils/I18nConstants.java b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/utils/I18nConstants.java
index 0cbc9ded6..add24e6e8 100644
--- a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/utils/I18nConstants.java
+++ b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/utils/I18nConstants.java
@@ -226,4 +226,8 @@ public class I18nConstants {
   public final static String TERMINOLOGY_PASSTHROUGH_TX_MESSAGE = "Terminology_PassThrough_TX_Message";
   public final static String FIXED_TYPE_CHECKS_DT_ADDRESS_LINE = "Fixed_Type_Checks_DT_Address_Line";
   public final static String MUSTSUPPORT_VAL_MUSTSUPPORT = "MustSupport_VAL_MustSupport";
+  public final static String ALL_OBSERVATIONS_SHOULD_HAVE_AN_EFFECTIVEDATETIME_OR_AN_EFFECTIVEPERIOD = "All_observations_should_have_an_effectiveDateTime_or_an_effectivePeriod";
+  public final static String ALL_OBSERVATIONS_SHOULD_HAVE_A_PERFORMER = "All_observations_should_have_a_performer";
+  public final static String ALL_OBSERVATIONS_SHOULD_HAVE_A_SUBJECT = "All_observations_should_have_a_subject";
+
 }
diff --git a/org.hl7.fhir.validation/src/main/resources/Messages.properties b/org.hl7.fhir.validation/src/main/resources/Messages.properties
index a8999d262..a5f5f2e3d 100644
--- a/org.hl7.fhir.validation/src/main/resources/Messages.properties
+++ b/org.hl7.fhir.validation/src/main/resources/Messages.properties
@@ -224,3 +224,6 @@ Terminology_TX_System_Unknown = Unknown Code System '{0}'
 Terminology_PassThrough_TX_Message = {0} for '{1}#{2}'
 Fixed_Type_Checks_DT_Address_Line = Expected {0} but found {1} line elements
 MustSupport_VAL_MustSupport = The element {0} is not marked as 'mustSupport' in the profile {1}. Consider not using the element, or marking the element as must-Support in the profile
+All_observations_should_have_an_effectiveDateTime_or_an_effectivePeriod = All observations should have an effectiveDateTime or an effectivePeriod
+All_observations_should_have_a_performer = All observations should have a performer
+All_observations_should_have_a_subject = All observations should have a subject
diff --git a/org.hl7.fhir.validation/src/main/resources/Messages_de_DE.properties b/org.hl7.fhir.validation/src/main/resources/Messages_de_DE.properties
index a8999d262..a5f5f2e3d 100644
--- a/org.hl7.fhir.validation/src/main/resources/Messages_de_DE.properties
+++ b/org.hl7.fhir.validation/src/main/resources/Messages_de_DE.properties
@@ -224,3 +224,6 @@ Terminology_TX_System_Unknown = Unknown Code System '{0}'
 Terminology_PassThrough_TX_Message = {0} for '{1}#{2}'
 Fixed_Type_Checks_DT_Address_Line = Expected {0} but found {1} line elements
 MustSupport_VAL_MustSupport = The element {0} is not marked as 'mustSupport' in the profile {1}. Consider not using the element, or marking the element as must-Support in the profile
+All_observations_should_have_an_effectiveDateTime_or_an_effectivePeriod = All observations should have an effectiveDateTime or an effectivePeriod
+All_observations_should_have_a_performer = All observations should have a performer
+All_observations_should_have_a_subject = All observations should have a subject