diff --git a/org.hl7.fhir.utilities/src/main/resources/Messages.properties b/org.hl7.fhir.utilities/src/main/resources/Messages.properties
index ca032b05c..7dc2bedf5 100644
--- a/org.hl7.fhir.utilities/src/main/resources/Messages.properties
+++ b/org.hl7.fhir.utilities/src/main/resources/Messages.properties
@@ -720,5 +720,5 @@ TX_SERVER_NO_BATCH_RESPONSE = The server return null from a batch validation req
 BUNDLE_POSSSIBLE_MATCHES = The bundle contains no match for {1} by the rules of Bundle reference resolution, but it has multiple resources that match {0} by resource type and id
 BUNDLE_BUNDLE_POSSIBLE_MATCH_NO_FU = Entry {0} matches the reference {1} by type and id but it does not match the full target URL {2} by Bundle resolution rules
 BUNDLE_BUNDLE_POSSIBLE_MATCH_WRONG_FU = Entry {0} matches the reference {1} by type and id but it''s fullUrl {2} does not match the full target URL {3} by Bundle resolution rules
-SD_ILLEGAL_CHARACTERISTICS = This element has a {0} but the types to do not make this kind of constraint relevant
+SD_ILLEGAL_CHARACTERISTICS = This element has a {0} but the types {1} to do not make this kind of constraint relevant
 SD_VALUE_COMPLEX_FIXED = For the complex type {0}, consider using a pattern rather than a fixed value to avoid over-constraining the instance
diff --git a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java
index c6f698b78..a37bd532d 100644
--- a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java
+++ b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java
@@ -149,7 +149,7 @@ public class StructureDefinitionValidator extends BaseValidator {
       addCharacteristics(tcharacteristics, tc);
       characteristics.addAll(tcharacteristics);
       if (type.hasChildren("targetProfile")) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), tcharacteristics.contains("has-target") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "targetProfile");
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), tcharacteristics.contains("has-target") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "targetProfile", tc);
       }
       // check the stated profile - must be a constraint on the type 
       if (snapshot || sd != null) {
@@ -165,7 +165,7 @@ public class StructureDefinitionValidator extends BaseValidator {
     }
     if (element.hasChild("binding")) {
       if (!typeCodes.isEmpty()) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("can-bind") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "Binding");
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("can-bind") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "Binding", typeCodes);
       }
       Element binding = element.getNamedChild("binding");
       validateBinding(errors, binding, stack.push(binding, -1, null, null), typeCodes, snapshot, element.getNamedChildValue("path"));
@@ -176,22 +176,22 @@ public class StructureDefinitionValidator extends BaseValidator {
     }
     if (!typeCodes.isEmpty()) {
       if (element.hasChild("maxLength")) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-length") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MaxLength");      
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-length") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MaxLength", typeCodes);      
       }
       if (element.hasExtension(ToolingExtensions.EXT_MIN_LENGTH)) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-length") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MinLength Extension");      
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-length") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MinLength Extension", typeCodes);      
       }
       if (element.hasChild("minValue")) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-range") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MinValue");      
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-range") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MinValue", typeCodes);      
       }
       if (element.hasChild("maxValue")) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-range") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MaxValue");      
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-range") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "MaxValue", typeCodes);      
       }
       if (element.hasExtension(ToolingExtensions.EXT_MAX_DECIMALS)) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("is-continuous") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "Max Decimal Places Extension");      
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("is-continuous") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "Max Decimal Places Extension", typeCodes);      
       }
       if (element.hasExtension(ToolingExtensions.EXT_MAX_SIZE)) {
-        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-size") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "Max Size");      
+        rule(errors, IssueType.BUSINESSRULE, stack.getLiteralPath(), characteristics.contains("has-size") , I18nConstants.SD_ILLEGAL_CHARACTERISTICS, "Max Size", typeCodes);      
       }
     }
     // in a snapshot, we validate that fixedValue, pattern, and defaultValue, if present, are all of the right type
@@ -285,7 +285,7 @@ public class StructureDefinitionValidator extends BaseValidator {
     case "Dosage" : return addCharacteristicsForType(set);
     case "Meta" :return  addCharacteristicsForType(set);
     case "Resource" :return  addCharacteristicsForType(set);
-    case "Extension" :return  addCharacteristicsForType(set);
+    case "Extension" :return  addCharacteristicsForType(set, "can-bind");
     case "Narrative" :return  addCharacteristicsForType(set);
     case "Element" :return  addCharacteristicsForType(set);
     case "BackboneElement" :return  addCharacteristicsForType(set);