diff --git a/DiscoveryServiceSpecification/V3.1_SSP-001.yaml b/DiscoveryServiceSpecification/V3.1_SSP-001.yaml
index 7262345a..e656a23b 100644
--- a/DiscoveryServiceSpecification/V3.1_SSP-001.yaml
+++ b/DiscoveryServiceSpecification/V3.1_SSP-001.yaml
@@ -135,10 +135,6 @@ paths:
                   $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part1-MetaModel-Schemas/V3.1.2#/components/schemas/SpecificAssetId'
         '400':
           $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/bad-request'
-        '404':
-          $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/not-found'
-        '409':
-          $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/conflict'
         default:
           $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/default'
     delete:
diff --git a/Entire-API-Collection/V3.1.yaml b/Entire-API-Collection/V3.1.yaml
index 383f5c5c..c88f5975 100644
--- a/Entire-API-Collection/V3.1.yaml
+++ b/Entire-API-Collection/V3.1.yaml
@@ -7313,10 +7313,6 @@ paths:
                   $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part1-MetaModel-Schemas/V3.1.2#/components/schemas/SpecificAssetId'
         '400':
           $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/bad-request'
-        '404':
-          $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/not-found'
-        '409':
-          $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/conflict'
         default:
           $ref: 'https://api.swaggerhub.com/domains/Plattform_i40/Part2-API-Schemas/V3.1.2#/components/responses/default'
     delete:
diff --git a/documentation/IDTA-01002-3/modules/ROOT/pages/changelog.adoc b/documentation/IDTA-01002-3/modules/ROOT/pages/changelog.adoc
index 05f7bfd0..b13a790e 100644
--- a/documentation/IDTA-01002-3/modules/ROOT/pages/changelog.adoc
+++ b/documentation/IDTA-01002-3/modules/ROOT/pages/changelog.adoc
@@ -9,6 +9,19 @@
 Note: Changes in Metamodel (IDTA-01001) will not be listed here, although they have an impact on the payload of many operations.
 ====
 
+== Changes w.r.t. V3.1.2 to V3.1.3
+
+Major Changes:
+
+* ...
+
+
+Minor Changes:
+
+* Fixed the response payload type of `PutSubmodelById` in the Asset Administration Shell Repository OpenAPI files: status code `201` now returns a `Submodel` instead of a `Reference`. (https://github.com/admin-shell-io/aas-specs-api/issues/601[#601])
+* Updated the response contract of `PostAllAssetLinksById` in Discovery OpenAPI files by removing status code `404` for `POST /lookup/shells/{aasIdentifier}` to align with create-or-replace semantics. (https://github.com/admin-shell-io/aas-specs-api/issues/595[#595])
+* Updated the response contract of `PostAllAssetLinksById` in Discovery OpenAPI files by removing status code `409` for `POST /lookup/shells/{aasIdentifier}` to align with replace/update behavior on repeated payloads. (https://github.com/admin-shell-io/aas-specs-api/issues/596[#596])
+
 
 == Changes w.r.t. V3.1.1 to V3.1.2