diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1507c4a9..22b72e0f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,29 +4,107 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## Version 4.1
 
-### Added
+### Added ###
+
+- Section 1.3  Relation to other IDSA assets
+- Minor editorial changes
+
+### Changed ###
+
+- Updating front matter with Maintainers and Contributors
+- Proving RAM 4.1 as GitBook
+
+### Removed ###
+
+- none
+
+### Deprecated ###
 
 - none
-- Business Layer: Adding Participant Information Service
-- Business Layer: Adding activities in relation to roles.
-- IDSA Rulebook
 
+### Fixed ###
+
+- Fixing links, Figure numbering and typos.
+
+
+### Security ###
+
+- none
+
+## Version 4.0
+
+### Added ###
+
+- Section 2.12: Privacy in the Connected World
+- Section 3.5: Adding Functional Architecture of a connector and Data Exchange Services view
+- Section 3.5: Adding out of Band transfer
+- Section 3.4.2: Adding Crawling for self-descriptions
+- Section 4.3.9. adding Data Space instances
+- Section 4.3.10: Adding IDS Rulebook
+- Section 4.3.11: Adding Privacy Perspective
+- Added structural elements in README files
 
 ### Changed
+
+- Section 1.1: Editorial Changess
+- Section 1.2.: Editorial Changes
+- Section 2: Editorial Changes
+- Changed Information layer from section 3.4 to section 3.3
+- Changed Process Layer from section 3.3 to section 3.4
+- Information Layer is shortend and references to Information Model documentation
+- Updates on Process Layer adding various details to processes
+- Section 3.1: updating Business Layer descriptions
+- Section 3.2: Editorial Updates
+- Section 3.5: adding various details
+- Section 4.1: major rework of structure and adding various details
+- Section 4.2: Major rework to align with current status of IDS Certification
+- Section 4.3: Editorial Updates
+- Updating front matter with Maintainers and Contributors
+
+### Removed ###
+
 - none
 - Business Layer: editorial changes.
 
-### Removed
+### Deprecated ###
+
 - none
 
-### Deprecated
+### Fixed ###
+
+- Fixing links, Figure numbering and typos.
+
+
+### Security ###
+
+- none
+
+## [Unreleased] ##
+
+### Added ###
+
 - none
 
-### Fixed
+### Changed ###
+- none
+
+
+### Removed ###
+
+- none
+
+### Deprecated ###
+
 - none
 - Business Layer: fixed consistency in Role Interaction table.
 
-### Security
+### Fixed ###
+
 - none
+
+
+### Security ###
+
+- none
\ No newline at end of file
diff --git a/documentation/1_Introduction/1_3_Relation_to_other_assets b/documentation/1_Introduction/1_3_Relation_to_other_assets
index 0f296e68..cbbddc7b 100644
--- a/documentation/1_Introduction/1_3_Relation_to_other_assets
+++ b/documentation/1_Introduction/1_3_Relation_to_other_assets
@@ -1,4 +1,4 @@
-## Relation to other IDSA assets
+## Relation to other IDSA assets ##
 
 Based on this Reference Architecture Model a Certification Scheme is derived that validates the compliance of [participants](../3_Layers_of_the_Reference_Architecture_Model/3_1_Business_Layer/3_1_1_Roles_in_the_IDS.md) and [components](../3_Layers_of_the_Reference_Architecture_Model/3_5_System_Layer/3_5_0_System_Layer.md) to this Reference Architecture Model. Such components can be provided as Free and Open Source Software or proprietary software. The operation of a data space instance is described in the [IDSA Rulebook](../4_Perspectives_of_the_Reference_Architecture_Model/4_3_Governance_Perspective/4_3_10_IDS_RuleBook.md) based on the BLOFT (**B**usiness, **L**egal, **O**perational, **F**unctional, **T**echnical) aspects of a data space.
 
diff --git a/documentation/3_Layers_of_the_Reference_Architecture_Model/3_1_Business_Layer/3_1_4_Usage_Contracts.md b/documentation/3_Layers_of_the_Reference_Architecture_Model/3_1_Business_Layer/3_1_4_Usage_Contracts.md
index e9b317e6..c38e5691 100644
--- a/documentation/3_Layers_of_the_Reference_Architecture_Model/3_1_Business_Layer/3_1_4_Usage_Contracts.md
+++ b/documentation/3_Layers_of_the_Reference_Architecture_Model/3_1_Business_Layer/3_1_4_Usage_Contracts.md
@@ -22,7 +22,6 @@ describes a certain permission or obligation of an [IDS Resource](../3_3_Informa
 Usage Contracts are written in a machine-readable
 format (according to the [IDS Usage Policy Language](../../4_Perspectives_of_the_Reference_Architecture_Model/4_1_Security_Perspective/4_1_6_Usage_Control.md#ids-usage-control-language)) and must
 be interpreted as [defined](../3_4_Process_Layer/3_4_6_Policy_Enforcement.md). In any
-
 case, a Usage Contract must always be regarded as an extension of an
 existing legal agreement between two IDS participants, which can be
 overruled by them. As neither the IDS nor any other known technology