diff --git a/src/ValueDefinitions/StringConstant.cpp b/src/ValueDefinitions/StringConstant.cpp
index ab1a9a6c26fef115051633b4bf844012d7bfb65a..8da3485770333410033a653106b2bfa9ef90c7bf 100644
--- a/src/ValueDefinitions/StringConstant.cpp
+++ b/src/ValueDefinitions/StringConstant.cpp
@@ -2,7 +2,7 @@
 // Class StringConstant
 //   The STRING CONSTANT definition.
 //
-// Copyright (c) 2000 - 2021, Paul Scherrer Institut, Villigen PSI, Switzerland
+// Copyright (c) 2000 - 2023, Paul Scherrer Institut, Villigen PSI, Switzerland
 // All rights reserved
 //
 // This file is part of OPAL.
@@ -36,7 +36,7 @@ StringConstant::StringConstant():
 
     registerOwnership(AttributeHandler::STATEMENT);
 
-    OpalData *opal = OpalData::getInstance();
+    OpalData* opal = OpalData::getInstance();
     opal->create(new StringConstant("GITREVISION", this, Util::getGitRevision()));
 
     // NOTE: Strings that contain a hyphen can't be written without quotes and
@@ -54,6 +54,7 @@ StringConstant::StringConstant():
     CREATE_STRINGCONSTANT("STANDING");
     CREATE_STRINGCONSTANT("TEMPORAL");
     CREATE_STRINGCONSTANT("SPATIAL");
+
     // Beam / PARTICLE
     CREATE_STRINGCONSTANT("ELECTRON");
     CREATE_STRINGCONSTANT("PROTON");
@@ -67,6 +68,7 @@ StringConstant::StringConstant():
     CREATE_STRINGCONSTANT("XENON");
     CREATE_STRINGCONSTANT("H2P");
     CREATE_STRINGCONSTANT("ALPHA");
+
     // Distribution / TYPE
     CREATE_STRINGCONSTANT("FROMFILE");
     CREATE_STRINGCONSTANT("GAUSS");
@@ -127,11 +129,11 @@ StringConstant::StringConstant():
 
     // OutputPlane / PLACEMENT_STYLE
     CREATE_STRINGCONSTANT("CENTRE_NORMAL");
-    CREATE_STRINGCONSTANT("PROBE");
+    // additionally: PROBE;
 
     // OutputPlane / ALGORITHM
     CREATE_STRINGCONSTANT("INTERPOLATION");
-    // CREATE_STRINGCONSTANT("RK4");
+    // additionally: RK4;
 
     // ParticleMatterInteraction / TYPE
     CREATE_STRINGCONSTANT("SCATTERING");
@@ -274,44 +276,41 @@ StringConstant::StringConstant():
     CREATE_STRINGCONSTANT("CYLINDRICAL");
 }
 
-StringConstant::StringConstant(const std::string &name, StringConstant *parent):
-    ValueDefinition(name, parent)
-{}
+StringConstant::StringConstant(const std::string& name,
+                               StringConstant* parent)
+    : ValueDefinition(name, parent) {
+}
 
+StringConstant::StringConstant(const std::string& name,
+                               StringConstant* parent,
+                               const std::string& value)
+    : ValueDefinition(name, parent) {
 
-StringConstant::StringConstant(const std::string &name, StringConstant *parent, const std::string &value):
-    ValueDefinition(name, parent)
-{
     Attributes::setString(itsAttr[0], value);
     itsAttr[0].setReadOnly(true);
     builtin = true;
 }
 
-
 StringConstant::~StringConstant()
 {}
 
-
-bool StringConstant::canReplaceBy(Object *) {
+bool StringConstant::canReplaceBy(Object*) {
     return false;
 }
 
-
-StringConstant *StringConstant::clone(const std::string &name) {
+StringConstant *StringConstant::clone(const std::string& name) {
     return new StringConstant(name, this);
 }
 
-
 std::string StringConstant::getString() const {
     return Attributes::getString(itsAttr[0]);
 }
 
-
-void StringConstant::print(std::ostream &os) const {
+void StringConstant::print(std::ostream& os) const {
     os << "STRING " << getOpalName() << '=' << itsAttr[0] << ';';
     os << std::endl;
 }
 
-void StringConstant::printValue(std::ostream &os) const {
+void StringConstant::printValue(std::ostream& os) const {
     os << itsAttr[0];
 }
diff --git a/src/ValueDefinitions/StringConstant.h b/src/ValueDefinitions/StringConstant.h
index 060d008ed2416a39c070f080091390fb5231a78a..def0a4cb8753306e733f1624b037c20d28cfa226 100644
--- a/src/ValueDefinitions/StringConstant.h
+++ b/src/ValueDefinitions/StringConstant.h
@@ -2,7 +2,7 @@
 // Class StringConstant
 //   The STRING CONSTANT definition.
 //
-// Copyright (c) 2000 - 2021, Paul Scherrer Institut, Villigen PSI, Switzerland
+// Copyright (c) 2000 - 2023, Paul Scherrer Institut, Villigen PSI, Switzerland
 // All rights reserved
 //
 // This file is part of OPAL.
@@ -24,7 +24,6 @@
 class StringConstant: public ValueDefinition {
 
 public:
-
     /// Exemplar constructor.
     StringConstant();
 
@@ -32,29 +31,28 @@ public:
 
     /// Test if object can be replaced.
     //  True, if [b]rhs[/b] is a string constant.
-    virtual bool canReplaceBy(Object *object);
+    virtual bool canReplaceBy(Object* object);
 
     /// Make clone.
-    virtual StringConstant *clone(const std::string &name);
+    virtual StringConstant* clone(const std::string& name);
 
     /// Print the constant.
-    virtual void print(std::ostream &) const;
+    virtual void print(std::ostream&) const;
 
     /// Print its value
-    virtual void printValue(std::ostream &os) const;
+    virtual void printValue(std::ostream& os) const;
 
     /// Return value.
     virtual std::string getString() const;
 
 private:
-
     // Not implemented.
-    StringConstant(const StringConstant &);
-    void operator=(const StringConstant &);
+    StringConstant(const StringConstant&);
+    void operator=(const StringConstant&);
 
     // Clone constructor.
-    StringConstant(const std::string &name, StringConstant *parent);
-    StringConstant(const std::string &name, StringConstant *parent, const std::string &value);
+    StringConstant(const std::string& name, StringConstant* parent);
+    StringConstant(const std::string& name, StringConstant* parent, const std::string& value);
 };
 
-#endif // OPAL_StringConstant_HH
\ No newline at end of file
+#endif // OPAL_StringConstant_HH