diff --git a/src/TNL/File.h b/src/TNL/File.h
index 7a8a024dbf086f556ed28bbf0df8e1d09bbbcb5e..8ccfe90b1b592842b80e7515a027e4e6f670bc1b 100644
--- a/src/TNL/File.h
+++ b/src/TNL/File.h
@@ -36,9 +36,8 @@ enum class IOMode
  */
 const size_t FileGPUvsCPUTransferBufferSize = 5 * 2<<20;
 
-/*
- * This file is aimed mainly for the binary data. It supports transparent compression.
- */
+
+/// Class file is aimed mainly for the binary data. It supports transparent compression.
 class File
 {
    IOMode mode;
@@ -55,10 +54,19 @@ class File
 
    public:
 
+   /// Basic constructor.
    File();
 
+   /// Destructor.
    ~File();
 
+   /////
+   /// \brief Opens given file. 
+   ///
+   /// Opens file with given \e fileName and returns true/false based on the success in opening the file.
+   /// \param fileName String which indicates name of the file user wants to open.
+   /// \param mode Indicates what user needs to do with opened file.
+   /// Modes to choose: IOMode::read or IOMode::write.
    bool open( const String& fileName,
               const IOMode mode );
 
@@ -92,6 +100,7 @@ class File
    template< typename Type, typename Device = Devices::Host >
    bool write( const Type* buffer );
 
+   /// \brief Closes given file and returns true/false based on the success in closing the file.
    bool close();
 
 protected:
diff --git a/src/TNL/Timer.h b/src/TNL/Timer.h
index 13567a438d84ba96e8ddfe934ebf3bd2c1ded104..a0bd36ae8ba7eab26cc96bfbf25ce1b80e598e65 100644
--- a/src/TNL/Timer.h
+++ b/src/TNL/Timer.h
@@ -66,10 +66,10 @@ class Timer
  
    protected:
 
-      /// Function for reading the real time from timer.
+      /// Function for reading the real time.
       double readRealTime() const;
 
-      /// \brief Function for reading the CPU time from timer.
+      /// \brief Function for reading the CPU time.
       ///
       /// CPU time is the time that measures how long it takes processor
       /// to complete all computations.
@@ -84,7 +84,7 @@ class Timer
  
    unsigned long long int initialCPUCycles, totalCPUCycles;
 
-   /// \brief Saves information about state of the timer. 
+   /// \brief Saves information about state of the timer.
    ///
    /// Knows whether the timer is currently stopped or not.
    bool stopState;