diff --git a/code/internal/+openminds/+abstract/ControlledTerm.m b/code/internal/+openminds/+abstract/ControlledTerm.m
index fce42393..5beb166b 100644
--- a/code/internal/+openminds/+abstract/ControlledTerm.m
+++ b/code/internal/+openminds/+abstract/ControlledTerm.m
@@ -1,10 +1,6 @@
-classdef (Abstract) ControlledTerm < openminds.abstract.Schema
+classdef (Abstract) ControlledTerm < openminds.abstract.ControlledTermBase
 %ControlledTerm Abstract base class for metadata types of the controlled terms module
 
-    properties (Access = protected)
-        Required = {'name'}
-    end
-    
     properties
         % Enter one sentence for defining this term.
         definition (1,1) string
@@ -12,15 +8,18 @@
         % Enter a short text describing this term.
         description (1,1) string
 
-        % Enter the internationalized resource identifier (IRI) pointing to the integrated ontology entry in the InterLex project.
-        interlexIdentifier (1,1) string
-
-        % Enter the internationalized resource identifier (IRI) pointing to the wiki page of the corresponding term in the KnowledgeSpace.
-        knowledgeSpaceLink (1,1) string
-
         % Controlled term originating from a defined terminology.
         name (1,1) string
 
+        % Enter all IRIs pointing to cross-references to external databases or registries that are equivalent to this term.
+        otherCrossReference (1,:) string {mustBeListOfUniqueItems(otherCrossReference)}
+
+        % Enter all IRIs pointing to ontology entries that are equivalent to this term.
+        otherOntologyIdentifier (1,:) string {mustBeListOfUniqueItems(otherOntologyIdentifier)}
+
+        % Enter the IRI pointing to the preferred cross-reference to an external database or registry.
+        preferredCrossReference (1,1) string
+
         % Enter the internationalized resource identifier (IRI) pointing to the preferred ontological term.
         preferredOntologyIdentifier (1,1) string
 
@@ -28,139 +27,15 @@
         synonym (1,:) string {mustBeListOfUniqueItems(synonym)}
     end
 
-    properties (SetAccess = protected, Hidden) % Todo: Same as id, clean up
-        at_id
-    end
-       
-    properties (Constant, Hidden)
-        LINKED_PROPERTIES = struct()
-        EMBEDDED_PROPERTIES = struct()
-    end
-
-    properties (Abstract, Constant, Hidden)
-        CONTROLLED_INSTANCES
-    end
-
     methods
         function obj = ControlledTerm(instanceSpec, propValues)
-            
             arguments
                 instanceSpec = []
                 propValues.?openminds.abstract.ControlledTerm
                 propValues.id (1,1) string
             end
 
-            if isstring(instanceSpec) && isscalar(instanceSpec) && instanceSpec == ""
-                instanceSpec = string.empty;
-            end
-
-            if ~isempty(instanceSpec)
-                if ischar(instanceSpec)
-                    instanceSpec = string(instanceSpec);
-                end
-
-                if isstring( instanceSpec ) && ~ismissing(instanceSpec)
-                    % Check IRI first, because isfile will also check IRIs
-                    % and that is expensive (we only want to check local
-                    % files anyway)
-                    if startsWith(instanceSpec, openminds.constant.BaseURI)
-                        obj.deserializeFromName(instanceSpec);
-                    elseif isfile( instanceSpec )
-                        obj.load( instanceSpec ) % todo: Not implemented??
-                    else
-                        % Deserialize from name of controlled instance
-                        obj.deserializeFromName(instanceSpec);
-                    end
-                elseif isstruct( instanceSpec ) && isfield(instanceSpec, 'at_id') || isfield(instanceSpec, 'x_id')
-                    numInstances = numel(instanceSpec);
-                    if numInstances > 1
-                        obj(numInstances) = feval(class(obj));
-                    end
-                    for i = 1:numel(instanceSpec)
-                        if isfield(instanceSpec(i), 'at_id')
-                            iri = instanceSpec(i).at_id;
-                        elseif isfield(instanceSpec(i), 'x_id')
-                            iri = instanceSpec(i).x_id;
-                        end
-                        obj(i).deserializeFromName(iri);
-                    end
-                else
-                    error('openMINDS:ControlledTerm:InvalidInput', ...
-                        'Expected instance spec to be a name, a filename or a structure with `at_id` field.')
-                end
-
-                names = fieldnames(propValues);
-                obj.warnIfPropValuesSupplied(names)
-            else
-                obj.set(propValues)
-                if ismissing(obj.id)
-                    obj.id = obj.generateInstanceId();
-                end
-            end
-        end
-    end
-    
-    methods (Access = protected) % Implement method for the CustomInstanceDisplay mixin
-        function str = getDisplayLabel(obj)
-            str = sprintf('%s', obj.name);
-        end
-    end
-
-    methods (Hidden)
-        function str = char(obj)
-            str = char(string(obj.name));
-        end
-    end
-
-    methods (Access = private)
-        function deserializeFromName(obj, instanceName)
-
-            import openminds.internal.getControlledInstance
-            import openminds.internal.utility.getSchemaName
-
-            instanceName = char(instanceName);
-            schemaName = getSchemaName(class(obj));
-
-            if openminds.utility.isIRI(instanceName)
-                if openminds.utility.isInstanceIRI(instanceName)
-                     [~, instanceName] = openminds.utility.parseInstanceIRI(instanceName);
-                else
-                    obj.id = instanceName;
-                    return
-                end
-            end
-            
-            [instanceName, instanceNameOrig] = deal(instanceName);
-            if ~any(strcmp(obj.CONTROLLED_INSTANCES, instanceName))
-                % Try to make a valid name
-                instanceName = strrep(instanceName, ' ', '');
-                instanceName = matlab.lang.makeValidName(instanceName, 'ReplacementStyle', 'delete');
-            end
-
-            % Todo: Use a proper deserializer
-            if any(strcmpi(obj.CONTROLLED_INSTANCES, instanceName))
-                try
-                    data = getControlledInstance(instanceName, schemaName, 'controlledTerms');
-                catch
-                    s = warning('off', 'backtrace');
-                    warningCleanup = onCleanup(@() warning(s));
-                    warning('Controlled instance "%s" is not available.', instanceNameOrig)
-                    return
-                end
-            else
-                warning('No matching instances were found for name "%s"', instanceName)
-                return
-                % error('Deserialization from user instance is not implemented yet')
-            end
-            propNames = {'at_id', 'name', 'definition', 'description', 'interlexIdentifier', 'knowledgeSpaceLink', 'preferredOntologyIdentifier', 'synonym'};
-
-            for i = 1:numel(propNames)
-                if ~isempty( data.(propNames{i}) )
-                    obj.(propNames{i}) = data.(propNames{i});
-                end
-            end
-
-            obj.id = obj.at_id;
+            obj.initializeControlledTerm(instanceSpec, propValues)
         end
     end
 end
diff --git a/code/internal/+openminds/+abstract/ControlledTermBase.m b/code/internal/+openminds/+abstract/ControlledTermBase.m
new file mode 100644
index 00000000..b7ce6dd1
--- /dev/null
+++ b/code/internal/+openminds/+abstract/ControlledTermBase.m
@@ -0,0 +1,171 @@
+classdef (Abstract) ControlledTermBase < openminds.abstract.Schema
+%ControlledTermBase Shared behavior for controlled term base classes.
+
+    properties (Access = protected)
+        Required = {'name'}
+    end
+
+    properties (SetAccess = protected, Hidden) % Todo: Same as id, clean up
+        at_id
+    end
+
+    properties (Constant, Hidden)
+        LINKED_PROPERTIES = struct()
+        EMBEDDED_PROPERTIES = struct()
+    end
+
+    properties (Abstract, Constant, Hidden)
+        CONTROLLED_INSTANCES
+    end
+
+    methods (Access = protected)
+        function initializeControlledTerm(obj, instanceSpec, propValues)
+            if isstring(instanceSpec) && isscalar(instanceSpec) && instanceSpec == ""
+                instanceSpec = string.empty;
+            end
+
+            if ~isempty(instanceSpec)
+                if ischar(instanceSpec)
+                    instanceSpec = string(instanceSpec);
+                end
+
+                if isstring( instanceSpec ) && ~ismissing(instanceSpec)
+                    % Check IRI first, because isfile will also check IRIs
+                    % and that is expensive (we only want to check local
+                    % files anyway)
+                    if startsWith(instanceSpec, openminds.constant.BaseURI)
+                        obj.deserializeFromName(instanceSpec);
+                    elseif isfile( instanceSpec )
+                        obj.load( instanceSpec ) % todo: Not implemented??
+                    else
+                        % Deserialize from name of controlled instance
+                        obj.deserializeFromName(instanceSpec);
+                    end
+                elseif isstruct( instanceSpec ) && (isfield(instanceSpec, 'at_id') || isfield(instanceSpec, 'x_id'))
+                    numInstances = numel(instanceSpec);
+                    if numInstances > 1
+                        obj(numInstances) = feval(class(obj));
+                    end
+                    for i = 1:numel(instanceSpec)
+                        if isfield(instanceSpec(i), 'at_id')
+                            iri = instanceSpec(i).at_id;
+                        elseif isfield(instanceSpec(i), 'x_id')
+                            iri = instanceSpec(i).x_id;
+                        end
+                        obj(i).deserializeFromName(iri);
+                    end
+                else
+                    error('openMINDS:ControlledTerm:InvalidInput', ...
+                        'Expected instance spec to be a name, a filename, or a structure or structure array with an `at_id` or `x_id` field.')
+                end
+
+                names = fieldnames(propValues);
+                obj.warnIfPropValuesSupplied(names)
+            else
+                obj.set(propValues)
+                if ismissing(obj.id) || obj.id == ""
+                    obj.id = obj.generateInstanceId();
+                end
+            end
+        end
+
+        function str = getDisplayLabel(obj)
+            str = sprintf('%s', obj.name);
+        end
+    end
+
+    methods (Hidden)
+        function str = char(obj)
+            str = char(string(obj.name));
+        end
+    end
+
+    methods (Access = private)
+        function deserializeFromName(obj, instanceName)
+
+            import openminds.internal.getControlledInstance
+            import openminds.internal.utility.getSchemaName
+
+            instanceName = char(instanceName);
+            instanceIRI = "";
+            schemaName = getSchemaName(class(obj));
+
+            if openminds.utility.isIRI(instanceName)
+                if openminds.utility.isInstanceIRI(instanceName)
+                     instanceIRI = string(instanceName);
+                     [~, instanceName] = openminds.utility.parseInstanceIRI(instanceName);
+                else
+                    obj.id = instanceName;
+                    return
+                end
+            end
+
+            if ~any(strcmp(obj.CONTROLLED_INSTANCES, instanceName))
+                % Try to make a valid name
+                instanceName = strrep(instanceName, ' ', '');
+                instanceName = matlab.lang.makeValidName(instanceName, 'ReplacementStyle', 'delete');
+            end
+
+            % Todo: Use a proper deserializer
+            isMatchingInstance = strcmpi(obj.CONTROLLED_INSTANCES, instanceName);
+            if any(isMatchingInstance)
+                instanceName = obj.CONTROLLED_INSTANCES(find(isMatchingInstance, 1, 'first'));
+                obj.name = instanceName;
+                if instanceIRI == ""
+                    obj.id = obj.createControlledInstanceIRI(schemaName, instanceName);
+                else
+                    obj.id = instanceIRI;
+                end
+
+                try
+                    data = getControlledInstance(instanceName, schemaName, 'controlledTerms');
+                catch
+                    % Known instance names are sufficient identifiers. The
+                    % JSON-LD instance file is only used to enrich metadata.
+                    return
+                end
+            else
+                warning('No matching instances were found for name "%s"', instanceName)
+                return
+                % error('Deserialization from user instance is not implemented yet')
+            end
+
+            propNames = [{'at_id'}, properties(obj)'];
+            for i = 1:numel(propNames)
+                if isfield(data, propNames{i}) && ~obj.isEmptyValue(data.(propNames{i}))
+                    obj.(propNames{i}) = data.(propNames{i});
+                end
+            end
+
+            if instanceIRI == "" && ~obj.isEmptyValue(obj.at_id)
+                obj.id = obj.at_id;
+            end
+        end
+    end
+
+    methods (Static, Access = private)
+        function instanceIRI = createControlledInstanceIRI(schemaName, instanceName)
+            instanceIRI = openminds.constant.BaseURI + "/instances/" ...
+                + openminds.abstract.ControlledTermBase.getInstanceTypeName(schemaName) ...
+                + "/" + string(instanceName);
+        end
+
+        function typeName = getInstanceTypeName(schemaName)
+            typeName = char(schemaName);
+            if ~strcmp(upper(typeName(1:2)), typeName(1:2))
+                typeName(1) = lower(typeName(1));
+            end
+            typeName = string(typeName);
+        end
+
+        function tf = isEmptyValue(value)
+            if isempty(value)
+                tf = true;
+            elseif isstring(value)
+                tf = all(ismissing(value) | value == "");
+            else
+                tf = false;
+            end
+        end
+    end
+end
diff --git a/code/internal/+openminds/+abstract/private/controlledTerms/v2/ControlledTerm.m b/code/internal/+openminds/+abstract/private/controlledTerms/v2/ControlledTerm.m
new file mode 100644
index 00000000..fe4ed0c3
--- /dev/null
+++ b/code/internal/+openminds/+abstract/private/controlledTerms/v2/ControlledTerm.m
@@ -0,0 +1,38 @@
+classdef (Abstract) ControlledTerm < openminds.abstract.ControlledTermBase
+%ControlledTerm Abstract base class for metadata types of the controlled terms module
+
+    properties
+        % Enter one sentence for defining this term.
+        definition (1,1) string
+
+        % Enter a short text describing this term.
+        description (1,1) string
+
+        % Enter the internationalized resource identifier (IRI) pointing to the integrated ontology entry in the InterLex project.
+        interlexIdentifier (1,1) string
+
+        % Enter the internationalized resource identifier (IRI) pointing to the wiki page of the corresponding term in the KnowledgeSpace.
+        knowledgeSpaceLink (1,1) string
+
+        % Controlled term originating from a defined terminology.
+        name (1,1) string
+
+        % Enter the internationalized resource identifier (IRI) pointing to the preferred ontological term.
+        preferredOntologyIdentifier (1,1) string
+
+        % Enter one or several synonyms (including abbreviations) for this controlled term.
+        synonym (1,:) string {mustBeListOfUniqueItems(synonym)}
+    end
+
+    methods
+        function obj = ControlledTerm(instanceSpec, propValues)
+            arguments
+                instanceSpec = []
+                propValues.?openminds.abstract.ControlledTerm
+                propValues.id (1,1) string
+            end
+
+            obj.initializeControlledTerm(instanceSpec, propValues)
+        end
+    end
+end
diff --git a/code/internal/+openminds/+abstract/private/controlledTerms/v3/ControlledTerm.m b/code/internal/+openminds/+abstract/private/controlledTerms/v3/ControlledTerm.m
new file mode 100644
index 00000000..5beb166b
--- /dev/null
+++ b/code/internal/+openminds/+abstract/private/controlledTerms/v3/ControlledTerm.m
@@ -0,0 +1,41 @@
+classdef (Abstract) ControlledTerm < openminds.abstract.ControlledTermBase
+%ControlledTerm Abstract base class for metadata types of the controlled terms module
+
+    properties
+        % Enter one sentence for defining this term.
+        definition (1,1) string
+
+        % Enter a short text describing this term.
+        description (1,1) string
+
+        % Controlled term originating from a defined terminology.
+        name (1,1) string
+
+        % Enter all IRIs pointing to cross-references to external databases or registries that are equivalent to this term.
+        otherCrossReference (1,:) string {mustBeListOfUniqueItems(otherCrossReference)}
+
+        % Enter all IRIs pointing to ontology entries that are equivalent to this term.
+        otherOntologyIdentifier (1,:) string {mustBeListOfUniqueItems(otherOntologyIdentifier)}
+
+        % Enter the IRI pointing to the preferred cross-reference to an external database or registry.
+        preferredCrossReference (1,1) string
+
+        % Enter the internationalized resource identifier (IRI) pointing to the preferred ontological term.
+        preferredOntologyIdentifier (1,1) string
+
+        % Enter one or several synonyms (including abbreviations) for this controlled term.
+        synonym (1,:) string {mustBeListOfUniqueItems(synonym)}
+    end
+
+    methods
+        function obj = ControlledTerm(instanceSpec, propValues)
+            arguments
+                instanceSpec = []
+                propValues.?openminds.abstract.ControlledTerm
+                propValues.id (1,1) string
+            end
+
+            obj.initializeControlledTerm(instanceSpec, propValues)
+        end
+    end
+end
diff --git a/code/internal/+openminds/+internal/activateControlledTermBase.m b/code/internal/+openminds/+internal/activateControlledTermBase.m
new file mode 100644
index 00000000..a8231e6b
--- /dev/null
+++ b/code/internal/+openminds/+internal/activateControlledTermBase.m
@@ -0,0 +1,46 @@
+function controlledTermVersion = activateControlledTermBase(modelVersion)
+%activateControlledTermBase Activate the controlled-term base for a model version.
+
+    arguments
+        modelVersion (1,1) openminds.internal.utility.VersionNumber ...
+            {openminds.mustBeValidVersion(modelVersion)} = "latest"
+    end
+
+    controlledTermVersion = getControlledTermVersion(modelVersion);
+
+    rootPath = openminds.internal.rootpath();
+    abstractFolder = fullfile(rootPath, "internal", "+openminds", "+abstract");
+    sourceFile = fullfile(abstractFolder, "private", "controlledTerms", ...
+        controlledTermVersion, "ControlledTerm.m");
+    targetFile = fullfile(abstractFolder, "ControlledTerm.m");
+
+    if ~isfile(sourceFile)
+        error("openMINDS:ControlledTerm:MissingVersionedBase", ...
+            'No controlled-term base exists for version "%s".', controlledTermVersion)
+    end
+
+    sourceText = fileread(sourceFile);
+    if isfile(targetFile)
+        targetText = fileread(targetFile);
+    else
+        targetText = '';
+    end
+
+    if ~strcmp(sourceText, targetText)
+        [success, message] = copyfile(sourceFile, targetFile, "f");
+        if ~success
+            error("openMINDS:ControlledTerm:ActivationFailed", ...
+                'Could not activate controlled-term base "%s": %s', ...
+                controlledTermVersion, message)
+        end
+        rehash
+    end
+end
+
+function controlledTermVersion = getControlledTermVersion(modelVersion)
+    if modelVersion >= 5
+        controlledTermVersion = "v3";
+    else
+        controlledTermVersion = "v2";
+    end
+end
diff --git a/code/internal/+openminds/selectOpenMindsVersion.m b/code/internal/+openminds/selectOpenMindsVersion.m
index dd9a3412..ca8f49c3 100644
--- a/code/internal/+openminds/selectOpenMindsVersion.m
+++ b/code/internal/+openminds/selectOpenMindsVersion.m
@@ -50,6 +50,8 @@ function selectOpenMindsVersion(versionNumber)
     addpath( genpath( fullfile(rootPath, 'internal') ) )
     addpath( genpath( fullfile(rootPath, 'livescripts') ) )
 
+    openminds.internal.activateControlledTermBase(versionNumber);
+
     % Get version number as string matching version numbers of version folders
     if versionNumber == "latest"
         versionAsString = 'latest';
@@ -69,6 +71,10 @@ function selectOpenMindsVersion(versionNumber)
     addpath(genpath( fullfile(rootPath, "mixedtypes", versionAsString) ))
     addpath(genpath( fullfile(rootPath, "enumerations", versionAsString) ))
 
+    % Version selection can replace shared abstract class files.
+    % Clear cached class definitions so MATLAB sees the active files.
+    clear classes;
+
     % Add a second pause for changes to take effect.
     pause(1) % Ad hoc value. Usually at least 0.3 - 0.4 seconds is necessary
 end
diff --git a/tools/.codespellrc b/tools/.codespellrc
index 43c87aa5..6f91bf24 100644
--- a/tools/.codespellrc
+++ b/tools/.codespellrc
@@ -1,3 +1,3 @@
 [codespell]
 skip = 
-ignore-words-list = ALS,ans
+ignore-words-list = TE,ALS,ans
diff --git a/tools/tests/unitTests/ControlledTermTest.m b/tools/tests/unitTests/ControlledTermTest.m
new file mode 100644
index 00000000..fb4db624
--- /dev/null
+++ b/tools/tests/unitTests/ControlledTermTest.m
@@ -0,0 +1,59 @@
+classdef ControlledTermTest < matlab.unittest.TestCase
+
+    methods (Test)
+        function testKnownInstanceCreatesLightweightReference(testCase)
+            term = testCase.verifyWarningFree( ...
+                @() openminds.controlledterms.ContributionType("authoring"));
+
+            testCase.verifyEqual(term.name, "authoring")
+            testCase.verifyEqual(term.id, ...
+                openminds.constant.BaseURI + "/instances/contributionType/authoring")
+        end
+
+        function testOlderControlledTermPropertiesAreAccepted(testCase)
+            sourceText = fileread(testCase.getControlledTermBasePath("v2"));
+
+            testCase.verifyTrue(contains(sourceText, "interlexIdentifier"))
+            testCase.verifyTrue(contains(sourceText, "knowledgeSpaceLink"))
+            testCase.verifyFalse(contains(sourceText, "otherCrossReference"))
+        end
+
+        function testNewerControlledTermPropertiesAreAccepted(testCase)
+            term = openminds.controlledterms.ContributionType( ...
+                [], ...
+                "name", "authoring", ...
+                "preferredCrossReference", "https://example.org/preferred", ...
+                "otherCrossReference", "https://example.org/cross-reference", ...
+                "otherOntologyIdentifier", "https://example.org/ontology");
+
+            testCase.verifyEqual(term.preferredCrossReference, "https://example.org/preferred")
+            testCase.verifyEqual(term.otherCrossReference, "https://example.org/cross-reference")
+            testCase.verifyEqual(term.otherOntologyIdentifier, "https://example.org/ontology")
+        end
+
+        function testLatestControlledTermBaseDoesNotExposeOlderProperties(testCase)
+            term = openminds.controlledterms.ContributionType();
+            propertyNames = string(properties(term));
+
+            testCase.verifyFalse(ismember("interlexIdentifier", propertyNames))
+            testCase.verifyFalse(ismember("knowledgeSpaceLink", propertyNames))
+        end
+
+        function testControlledTermBaseDoesNotExposeTermSuggestionProperties(testCase)
+            term = openminds.controlledterms.ContributionType();
+            propertyNames = string(properties(term));
+
+            testCase.verifyFalse(ismember("addExistingTerminology", propertyNames))
+            testCase.verifyFalse(ismember("suggestNewTerminology", propertyNames))
+        end
+    end
+
+    methods (Access = private)
+        function filePath = getControlledTermBasePath(~, version)
+            rootPath = openminds.internal.rootpath();
+            filePath = fullfile(rootPath, "internal", "+openminds", ...
+                "+abstract", "private", "controlledTerms", version, ...
+                "ControlledTerm.m");
+        end
+    end
+end