diff --git a/src/blackcore/fsd/addpilot.h b/src/blackcore/fsd/addpilot.h
index 8e3765863..573b81051 100644
--- a/src/blackcore/fsd/addpilot.h
+++ b/src/blackcore/fsd/addpilot.h
@@ -25,7 +25,7 @@ namespace BlackCore
         class BLACKCORE_EXPORT AddPilot : public MessageBase
         {
         public:
-            // Constructor
+            //! Constructor
             AddPilot(const QString &callsign, const QString &cid, const QString &password, PilotRating rating, int protocolRevision, SimType simType, const QString &realName);
 
             //! Get user cid
diff --git a/src/blackcore/fsd/atcdataupdate.cpp b/src/blackcore/fsd/atcdataupdate.cpp
index 5188590bb..3d01b866d 100644
--- a/src/blackcore/fsd/atcdataupdate.cpp
+++ b/src/blackcore/fsd/atcdataupdate.cpp
@@ -52,7 +52,7 @@ namespace BlackCore
             {
                 BlackMisc::CLogMessage(static_cast<AtcDataUpdate *>(nullptr)).warning(u"Wrong number of arguments.");
                 return {};
-            };
+            }
 
             AtcDataUpdate packet(tokens[0], tokens[1].toInt() + 100000, fromQString<CFacilityType>(tokens[2]), tokens[3].toInt(), fromQString<AtcRating>(tokens[4]),
                                tokens[5].toDouble(), tokens[6].toDouble(), tokens[7].toInt());
diff --git a/src/blackcore/fsd/atcdataupdate.h b/src/blackcore/fsd/atcdataupdate.h
index 44d380b87..c4d80be0f 100644
--- a/src/blackcore/fsd/atcdataupdate.h
+++ b/src/blackcore/fsd/atcdataupdate.h
@@ -24,6 +24,8 @@ namespace BlackCore
         //! FSD Message: ATC data update
         class BLACKCORE_EXPORT AtcDataUpdate : public MessageBase
         {
+            friend bool operator==(const AtcDataUpdate &, const AtcDataUpdate &);
+
         public:
             //! Constructor
             AtcDataUpdate(const QString &sender, int frequencykHz, BlackMisc::Network::CFacilityType facility, int visibleRange, AtcRating rating,
@@ -35,18 +37,21 @@ namespace BlackCore
             //! Construct from tokens
             static AtcDataUpdate fromTokens(const QStringList &tokens);
 
-            //! PDU identifier
-            static QString pdu() { return "%"; }
-
+            //! Properties @{
             int m_frequencykHz = 0.0;
             BlackMisc::Network::CFacilityType m_facility;
             int m_visibleRange = 0.0;
             AtcRating m_rating = AtcRating::Unknown;
-            double m_latitude = 0.0;
+            double m_latitude  = 0.0;
             double m_longitude = 0.0;
             int m_elevation = 0.0;
+            //! @}
+
+            //! PDU identifier
+            static QString pdu() { return "%"; }
 
         private:
+            //! Ctor
             AtcDataUpdate();
         };
 
diff --git a/src/blackcore/fsd/authresponse.h b/src/blackcore/fsd/authresponse.h
index 7da11d99b..7bb250a8a 100644
--- a/src/blackcore/fsd/authresponse.h
+++ b/src/blackcore/fsd/authresponse.h
@@ -34,7 +34,7 @@ namespace BlackCore
             //! PDU identifier
             static QString pdu() { return QStringLiteral("$ZR"); }
 
-            QString m_response;
+            QString m_response; //!< response
 
         private:
             AuthResponse();
diff --git a/src/blackcore/fsd/clientidentification.h b/src/blackcore/fsd/clientidentification.h
index 7d54e7354..dae9a1d35 100644
--- a/src/blackcore/fsd/clientidentification.h
+++ b/src/blackcore/fsd/clientidentification.h
@@ -37,6 +37,7 @@ namespace BlackCore
             //! PDU identifier
             static QString pdu() { return "$ID"; }
 
+            //! Properties @{
             std::uint16_t m_clientId = 0;
             QString m_clientName;
             int m_clientVersionMajor = BlackConfig::CBuildConfig::getVersion().majorVersion();
@@ -44,6 +45,7 @@ namespace BlackCore
             QString m_userCid;
             QString m_sysUid;
             QString m_initialChallenge;
+            //! @}
 
         private:
             ClientIdentification();
diff --git a/src/blackcore/fsd/clientresponse.h b/src/blackcore/fsd/clientresponse.h
index 3b2bbc25e..eef680478 100644
--- a/src/blackcore/fsd/clientresponse.h
+++ b/src/blackcore/fsd/clientresponse.h
@@ -25,6 +25,7 @@ namespace BlackCore
             //! Constructor
             ClientResponse(const QString &sender, const QString &receiver, ClientQueryType queryType, const QStringList &responseData);
 
+            //! Unknow query?
             bool isUnknownQuery() const { return m_queryType == ClientQueryType::Unknown; }
 
             //! Message converted to tokens
@@ -36,8 +37,10 @@ namespace BlackCore
             //! PDU identifier
             static QString pdu() { return "$CR"; }
 
+            //! Properties @{
             ClientQueryType m_queryType;
-            QStringList m_responseData;
+            QStringList     m_responseData;
+            //! @}
 
         private:
             ClientResponse();
diff --git a/src/blackcore/fsd/enums.h b/src/blackcore/fsd/enums.h
index 7f18600c0..2a17cdea5 100644
--- a/src/blackcore/fsd/enums.h
+++ b/src/blackcore/fsd/enums.h
@@ -171,12 +171,13 @@ namespace BlackCore
             AircraftConfig   = (1 << 8)
         };
 
+        //! Operators @{
         inline Capabilities operator | (Capabilities lhs, Capabilities rhs)
         {
             return static_cast<Capabilities>(static_cast<int>(lhs) | static_cast<int>(rhs));
         }
 
-        inline Capabilities& operator |= (Capabilities& lhs, Capabilities rhs)
+        inline Capabilities &operator |= (Capabilities &lhs, Capabilities rhs)
         {
             lhs = lhs | rhs;
             return lhs;
@@ -186,7 +187,9 @@ namespace BlackCore
         {
             return static_cast<int>(lhs) & static_cast<int>(rhs);
         }
+        //! @}
 
+        //! ATIS line type
         enum class AtisLineType
         {
             Unknown,
diff --git a/src/blackcore/fsd/flightplan.h b/src/blackcore/fsd/flightplan.h
index 2995fb6f6..f6b5c8642 100644
--- a/src/blackcore/fsd/flightplan.h
+++ b/src/blackcore/fsd/flightplan.h
@@ -37,6 +37,7 @@ namespace BlackCore
             //! PDU identifier
             static QString pdu() { return "$FP"; }
 
+            //! Properties @{
             FlightType m_flightType;
             QString m_aircraftIcaoType;
             int m_trueCruisingSpeed = 0;
@@ -52,6 +53,7 @@ namespace BlackCore
             QString m_altAirport;
             QString m_remarks;
             QString m_route;
+            //! @
 
         protected:
             FlightPlan();
diff --git a/src/blackcore/fsd/messagebase.h b/src/blackcore/fsd/messagebase.h
index ec18ea049..76d8d1d42 100644
--- a/src/blackcore/fsd/messagebase.h
+++ b/src/blackcore/fsd/messagebase.h
@@ -56,7 +56,6 @@ namespace BlackCore
 
             //! Constructor
             MessageBase(const QString &sender, const QString &receiver);
-            virtual ~MessageBase() {}
 
             //! Set callsign
             void setCallsign(const QString &sender) { m_sender = sender; }
diff --git a/src/blacksound/dsp/SimpleComp.h b/src/blacksound/dsp/SimpleComp.h
index 99d28de68..aa350b5a0 100644
--- a/src/blacksound/dsp/SimpleComp.h
+++ b/src/blacksound/dsp/SimpleComp.h
@@ -55,7 +55,7 @@ namespace chunkware_simple
         //! @{ get parameters
         virtual double getThresh(void) const { return threshdB_; }
         virtual double getRatio(void)  const { return ratio_; }
-        double getMakeUpGain(void) const { return makeUpGain_; }
+        double getMakeUpGain(void) const     { return makeUpGain_; }
         //! @}
 
         //! Init runtime
@@ -79,9 +79,7 @@ namespace chunkware_simple
 
     };  // end SimpleComp class
 
-    //-------------------------------------------------------------
-    // simple compressor with RMS detection
-    //-------------------------------------------------------------
+    //! Simple compressor with RMS detection
     class SimpleCompRms : public SimpleComp
     {
     public:
diff --git a/src/blacksound/dsp/SimpleEnvelope.h b/src/blacksound/dsp/SimpleEnvelope.h
index e7914f2c5..5cd514fb1 100644
--- a/src/blacksound/dsp/SimpleEnvelope.h
+++ b/src/blacksound/dsp/SimpleEnvelope.h
@@ -42,13 +42,16 @@ namespace chunkware_simple
     // USE:
     // 1. init envelope state to DC_OFFSET before processing
     // 2. add to input before envelope runtime function
-    static const double DC_OFFSET = 1.0E-25;
+    static constexpr double DC_OFFSET = 1.0E-25;
 
-    //! envelope detector
+    //! Envelope detector
     class EnvelopeDetector
     {
     public:
+        //! Ctor
         EnvelopeDetector(double ms = 1.0, double sampleRate = 44100.0);
+
+        //! Dtor
         virtual ~EnvelopeDetector() {}
 
         //! set time constant
@@ -70,34 +73,40 @@ namespace chunkware_simple
         }
 
     protected:
+        //! Set coefficients
+        virtual void setCoef(void); //!< coef calculation
 
         double sampleRate_;         //!< sample rate
         double ms_;                 //!< time constant in ms
         double coef_;               //!< runtime coefficient
-        virtual void setCoef(void); //!< coef calculation
-
     };  // end SimpleComp class
 
     //! attack/release envelope
     class AttRelEnvelope
     {
     public:
+        //! Ctor
         AttRelEnvelope(double att_ms = 10.0, double rel_ms = 100.0, double sampleRate = 44100.0);
+
+        //! Dtor
         virtual ~AttRelEnvelope() {}
 
-        // attack time constant
+        //! Attack time constant @{
         virtual void   setAttack(double ms);
         virtual double getAttack(void) const { return att_.getTc(); }
+        //! @}
 
-        // release time constant
+        //! Release time constant @{
         virtual void   setRelease(double ms);
         virtual double getRelease(void) const { return rel_.getTc(); }
+        //! @}
 
-        // sample rate dependencies
+        //! Sample rate dependencies @{
         virtual void   setSampleRate(double sampleRate);
         virtual double getSampleRate(void) const { return att_.getSampleRate(); }
+        //! @}
 
-        // runtime function
+        //! Runtime function
         INLINE void run(double in, double &state)
         {
 
@@ -114,7 +123,6 @@ namespace chunkware_simple
         }
 
     private:
-
         EnvelopeDetector att_;
         EnvelopeDetector rel_;
 
diff --git a/src/blacksound/dsp/SimpleGate.h b/src/blacksound/dsp/SimpleGate.h
index f73489207..a469dfc5c 100644
--- a/src/blacksound/dsp/SimpleGate.h
+++ b/src/blacksound/dsp/SimpleGate.h
@@ -28,8 +28,8 @@
  */
 
 
-#ifndef __SIMPLE_GATE_H__
-#define __SIMPLE_GATE_H__
+#ifndef chunkware__SIMPLE_GATE_H
+#define chunkware__SIMPLE_GATE_H
 
 #include "SimpleHeader.h"       // common header
 #include "SimpleEnvelope.h"     // for base class
@@ -53,11 +53,13 @@ namespace chunkware_simple
         //! get threshold
         virtual double getThresh(void) const { return threshdB_; }
 
-        // init runtime
-        virtual void initRuntime(void);              // call before runtime (in resume())
+        //! Init runtime
+        //! \remark call before runtime (in resume())
+        virtual void initRuntime(void);
 
         //! Process audio
-        void process(double &in1, double &in2);      // gate runtime process
+        //! \remark gate runtime process
+        void process(double &in1, double &in2);
 
         //! Process audio stereo-linked
         void process(double &in1, double &in2, double keyLinked);    // with stereo-linked key in
@@ -71,7 +73,7 @@ namespace chunkware_simple
         double env_;        //!< over-threshold envelope (linear)
     };
 
-    //! simple gate with RMS detection
+    //! Simple gate with RMS detection
     class SimpleGateRms : public SimpleGate
     {
     public:
diff --git a/src/blacksound/dsp/SimpleLimit.h b/src/blacksound/dsp/SimpleLimit.h
index 3792fb3e9..c82cc80cb 100644
--- a/src/blacksound/dsp/SimpleLimit.h
+++ b/src/blacksound/dsp/SimpleLimit.h
@@ -28,8 +28,8 @@
  */
 
 
-#ifndef __SIMPLE_LIMIT_H__
-#define __SIMPLE_LIMIT_H__
+#ifndef chunkware_SIMPLE_LIMIT_H
+#define chunkware_SIMPLE_LIMIT_H
 
 #include "SimpleHeader.h"       // common header
 #include "SimpleEnvelope.h"     // for base class of FastEnvelope
@@ -76,18 +76,21 @@ namespace chunkware_simple
 
     protected:
 
-        //! class for faster attack/release
+        //! Class for faster attack/release
         class FastEnvelope : public EnvelopeDetector
         {
         public:
+            //! Ctor
             FastEnvelope(double ms = 1.0, double sampleRate = 44100.0)
                 : EnvelopeDetector(ms, sampleRate)
             {}
-            virtual ~FastEnvelope() {}
+
+            //! Dtor
+            virtual ~FastEnvelope() override {}
 
         protected:
-            // override setCoef() - coefficient calculation
-            virtual void setCoef(void);
+            //! Override setCoef() - coefficient calculation
+            virtual void setCoef(void) override;
         };
 
     private:
@@ -123,4 +126,4 @@ namespace chunkware_simple
 // include inlined process function
 #include "SimpleLimitProcess.inl"
 
-#endif  // end __SIMPLE_LIMIT_H__
+#endif  // guard