diff --git a/src/TNL/String.h b/src/TNL/String.h
index 6e8ab71925da132d66a89aef20fe1e619b97871e..57219562e7e5c8389f26616f6e97f02742b1f40a 100644
--- a/src/TNL/String.h
+++ b/src/TNL/String.h
@@ -138,7 +138,7 @@ class String
       /// This function overloads operator!=().
       bool operator!=( char str ) const;
 
-      /// \brief Cast to bool operator.
+      /// \brief Cast to bool operator. Converts string to boolean expression (true or false).
       operator bool() const;
 
       /// \brief Cast to bool with negation operator.
@@ -161,25 +161,27 @@ class String
       /// @param separator Character, which separates substrings in given string. Empty character can not be used.
       int split( Containers::List< String >& list, const char separator = ' ' ) const;
 
-      /// Write to a binary file
+      /// Writes to a binary file and returns boolean expression based on the success in writing into the file.
       bool save( File& file ) const;
 
-      /// Read from binary file
+      /// Reads from binary file and returns boolean expression based on the success in reading the file.
       bool load( File& file );
 
-      //! Broadcast to other nodes in MPI cluster
+      /// !!! Mozem dat prec???
+      // Broadcast to other nodes in MPI cluster
       //   void MPIBcast( int root, MPI_Comm mpi_comm = MPI_COMM_WORLD );
 
-      /// Read one line from given stream.
+      /// Reads one line from given stream.
       bool getLine( std::istream& stream );
 
+      ///toto neviem co
       friend std::ostream& operator<<( std::ostream& stream, const String& str );
 
    protected:
-      /// Pointer to char ended with zero
+      /// Pointer to char ended with zero ...Preco?
       char* string;
 
-      /// Length of the allocated piece of memory
+      /// Length of the allocated piece of memory.
       int length;
 
 
@@ -191,6 +193,7 @@ String operator+( char string1, const String& string2 );
 /// Returns concatenation of \e string1 and \e string2.
 String operator+( const char* string1, const String& string2 );
 
+/// Toto neviem co
 std::ostream& operator<<( std::ostream& stream, const String& str );
 
 template< typename T >
diff --git a/src/UnitTests/StringTest.cpp b/src/UnitTests/StringTest.cpp
index f6664673ec6ba7da6ff5058205f0dd08b4e70236..9b85bd728c6db1a731b989cffa5b4bfa808209ac 100644
--- a/src/UnitTests/StringTest.cpp
+++ b/src/UnitTests/StringTest.cpp
@@ -309,7 +309,7 @@ TEST( StringTest, split )
    ASSERT_EQ( list.getSize(), 1 );
    EXPECT_EQ( list[ 0 ], "abracadabra" );
 
-   /// !!!!
+   /// !!!! ma problem s prazdnym stringom !!!!
    String( "a,,b,c" ).split( list, ',' );
    ASSERT_EQ( list.getSize(), 4 );
    EXPECT_EQ( list[ 0 ], "a" );
@@ -349,6 +349,12 @@ TEST( StringTest, getLine )
    EXPECT_EQ( s, "Line 2" );
 };
 
+/*TEST( StringTest, OperatorCudny )
+{
+    String str("String1");
+    EXPECT_EQ(strcmp(String( "a", str ), "aString1"), 0 );
+};*/
+
 #endif