diff --git a/src/PlugIn.cpp b/src/PlugIn.cpp
index 8e5b71f..450114b 100644
--- a/src/PlugIn.cpp
+++ b/src/PlugIn.cpp
@@ -36,8 +36,7 @@ using namespace aman;
 static std::string __receivedAmanData;
 
 static std::size_t receiveCurl(void* ptr, std::size_t size, std::size_t nmemb, void* stream) {
-    (void)stream;
-
+    std::ignore = stream;
     std::string serverResult = static_cast<char*>(ptr);
     __receivedAmanData += serverResult;
     return size * nmemb;
@@ -69,7 +68,7 @@ PlugIn::PlugIn() :
     /* get the dll-path */
     char path[MAX_PATH + 1] = { 0 };
     const gsl::span<char, MAX_PATH + 1> span(path);
-    GetModuleFileNameA((HINSTANCE)&__ImageBase, span.data(), span.size());
+    GetModuleFileNameA(gsl::narrow_cast<HINSTANCE>(&__ImageBase), span.data(), span.size());
     PathRemoveFileSpecA(span.data());
     std::string dllPath = span.data();
 
@@ -95,7 +94,7 @@ PlugIn::PlugIn() :
     this->validateBackendData();
 }
 
-PlugIn::~PlugIn() noexcept {
+PlugIn::~PlugIn() {
     Backend::instance().deinitialize();
     ZmqContext::instance().deinitialize();
     google::protobuf::ShutdownProtobufLibrary();
@@ -174,7 +173,7 @@ void PlugIn::validateBackendData() {
     }
 
     /* incompatible communication version */
-    if (PLUGIN_MAJOR_VERSION != std::atoi(entries[0].c_str()) || PLUGIN_MINOR_VERSION != std::atoi(entries[1].c_str())) {
+    if (PLUGIN_MAJOR_VERSION != std::atoi(gsl::at(entries, 0).c_str()) || PLUGIN_MINOR_VERSION != std::atoi(gsl::at(entries, 1).c_str())) {
         MessageBoxA(nullptr, "Plugin version is outdated. An update is required", "AMAN-Error", MB_OK);
         return;
     }
@@ -200,11 +199,11 @@ EuroScopePlugIn::CRadarScreen* PlugIn::OnRadarScreenCreated(const char* displayN
     return this->m_screen.get();
 }
 
-aman::Aircraft* PlugIn::generateAircraftMessage(EuroScopePlugIn::CRadarTarget& target) {
+aman::Aircraft* PlugIn::generateAircraftMessage(const EuroScopePlugIn::CRadarTarget& target) const {
     if (false == target.IsValid() || false == target.GetCorrelatedFlightPlan().IsValid())
         return nullptr;
 
-    auto flightPlan = target.GetCorrelatedFlightPlan();
+    const auto flightPlan = target.GetCorrelatedFlightPlan();
     std::string callsign(target.GetCallsign());
     aman::Aircraft* retval = new aman::Aircraft();
 
@@ -237,7 +236,7 @@ aman::Aircraft* PlugIn::generateAircraftMessage(EuroScopePlugIn::CRadarTarget& t
 }
 
 void PlugIn::generateAircraftReportMessage(EuroScopePlugIn::CRadarTarget& radarTarget, aman::AircraftReport* report) {
-    auto flightPlan = radarTarget.GetCorrelatedFlightPlan();
+    const auto flightPlan = radarTarget.GetCorrelatedFlightPlan();
 
     /* ignore invalid flightplans */
     if (false == flightPlan.IsValid())
@@ -252,12 +251,12 @@ void PlugIn::generateAircraftReportMessage(EuroScopePlugIn::CRadarTarget& radarT
         return;
 
     /* filter invalid destinations */
-    auto destination = std::string_view(flightPlan.GetFlightPlanData().GetDestination());
+    const auto destination = std::string_view(flightPlan.GetFlightPlanData().GetDestination());
     if (4 != destination.length())
         return;
 
     /* filter by distance to destination */
-    double distanceNM = flightPlan.GetDistanceToDestination();
+    const double distanceNM = flightPlan.GetDistanceToDestination();
     if (5.0 > distanceNM || 250.0 < distanceNM)
         return;
 
@@ -312,7 +311,7 @@ void PlugIn::generateAircraftReportMessage(EuroScopePlugIn::CRadarTarget& radarT
         auto split = String::splitString(element.GetName(), " ");
 
         /* find the correct star */
-        if (0 != split.size() && destination == split[0]) {
+        if (0 != split.size() && destination == gsl::at(split, 0)) {
             /* get the IAF */
             EuroScopePlugIn::CPosition position;
             if (true == element.GetPosition(&position, 0)) {
@@ -333,13 +332,13 @@ void PlugIn::generateAircraftReportMessage(EuroScopePlugIn::CRadarTarget& radarT
     }
 
     if (0 != iafName.length()) {
-        auto iafDistance = currentPosition.DistanceTo(iafPosition);
+        const auto iafDistance = currentPosition.DistanceTo(iafPosition);
 
         /* calculate the distance to the IAF */
         double distanceToIaf = 0.0f;
         for (int i = 1; i < flightPlan.GetPositionPredictions().GetPointsNumber(); ++i) {
-            double distance = flightPlan.GetPositionPredictions().GetPosition(i).DistanceTo(currentPosition);
-            double headingDelta = std::abs(radarTarget.GetPosition().GetReportedHeading() - flightPlan.GetPositionPredictions().GetPosition(i).DirectionTo(iafPosition));
+            const double distance = flightPlan.GetPositionPredictions().GetPosition(i).DistanceTo(currentPosition);
+            const double headingDelta = std::abs(radarTarget.GetPosition().GetReportedHeading() - flightPlan.GetPositionPredictions().GetPosition(i).DirectionTo(iafPosition));
 
             /*
              * 1. no direct way to IAF -> some direct given -> stop after lateral passing
@@ -371,9 +370,10 @@ void PlugIn::generateAircraftReportMessage(EuroScopePlugIn::CRadarTarget& radarT
 
     /* set the report time */
     std::stringstream stream;
-    auto reportTime = std::chrono::utc_clock::now();
+    const auto reportTime = std::chrono::utc_clock::now();
     stream << std::format("{0:%Y%m%d%H%M%S}", reportTime);
-    report->set_reporttime(String::splitString(stream.str(), ".")[0]);
+    const auto elements = String::splitString(stream.str(), ".");
+    report->set_reporttime(gsl::at(elements, 0));
 }
 
 bool PlugIn::OnCompileCommand(const char* cmdline) {
@@ -435,12 +435,13 @@ void PlugIn::OnGetTagItem(EuroScopePlugIn::CFlightPlan flightPlan, EuroScopePlug
     std::transform(destination.begin(), destination.end(), destination.begin(), ::toupper);
 #pragma warning(default: 4244)
 
-    bool planExpected, forced;
+    bool planExpected = false, forced = false;
+    const gsl::span<char, 16> tagString(itemString, 16UL);
 
     this->m_updateQueueLock.lock();
 
     /* check if the inbound is forced */
-    auto cIt = std::find(this->m_forcedToBackendCallsigns.cbegin(), this->m_forcedToBackendCallsigns.cend(), callsign);
+    const auto cIt = std::find(this->m_forcedToBackendCallsigns.cbegin(), this->m_forcedToBackendCallsigns.cend(), callsign);
     forced = this->m_forcedToBackendCallsigns.cend() != cIt;
 
     /* check if the inbound is expected to be planned */
@@ -475,7 +476,7 @@ void PlugIn::OnGetTagItem(EuroScopePlugIn::CFlightPlan flightPlan, EuroScopePlug
                     *colorCode = EuroScopePlugIn::TAG_COLOR_DEFAULT;
             }
             else {
-                itemString[0] = '\0';
+                gsl::at(tagString, 0) = '\0';
             }
         }
         else {
@@ -490,7 +491,7 @@ void PlugIn::OnFunctionCall(int functionId, const char* itemString, POINT pt, RE
     std::ignore = pt;
     std::ignore = area;
 
-    auto radarTarget = this->RadarTargetSelectASEL();
+    const auto radarTarget = this->RadarTargetSelectASEL();
     if (false == radarTarget.IsValid() || false == radarTarget.GetCorrelatedFlightPlan().IsValid())
         return;
 
diff --git a/src/PlugIn.h b/src/PlugIn.h
index feea05d..793aa3a 100644
--- a/src/PlugIn.h
+++ b/src/PlugIn.h
@@ -45,7 +45,7 @@ namespace aman {
         };
 
         void validateBackendData();
-        aman::Aircraft* generateAircraftMessage(EuroScopePlugIn::CRadarTarget& target);
+        aman::Aircraft* generateAircraftMessage(const EuroScopePlugIn::CRadarTarget& target) const;
         void generateAircraftReportMessage(EuroScopePlugIn::CRadarTarget& radarTarget, aman::AircraftReport* report);
         void addUpdateQueue(EuroScopePlugIn::CRadarTarget& radarTarget);
         void updateInbound(EuroScopePlugIn::CRadarTarget& radarTarget);
@@ -71,7 +71,7 @@ namespace aman {
         /**
          * @brief Destroys all internal strcutures
          */
-        ~PlugIn() noexcept;
+        ~PlugIn();
 
         PlugIn(const PlugIn&) = delete;
         PlugIn(PlugIn&&) = delete;
diff --git a/src/RadarScreen.cpp b/src/RadarScreen.cpp
index 261b8db..326fe41 100644
--- a/src/RadarScreen.cpp
+++ b/src/RadarScreen.cpp
@@ -15,7 +15,7 @@
 
 using namespace aman;
 
-RadarScreen::RadarScreen() :
+RadarScreen::RadarScreen() noexcept :
         EuroScopePlugIn::CRadarScreen() { }
 
 RadarScreen::~RadarScreen() { }
diff --git a/src/RadarScreen.h b/src/RadarScreen.h
index 13450b4..21fd8fc 100644
--- a/src/RadarScreen.h
+++ b/src/RadarScreen.h
@@ -22,7 +22,7 @@ namespace aman {
         /**
          * @brief Creates a new RADAR screen
          */
-        RadarScreen();
+        RadarScreen() noexcept;
         /**
          * @brief Destroys the internal structure
          */