@@ -12,7 +12,6 @@ enable_testing()
 
 add_subdirectory( src/ACEtk/Table/Data/Parse/test )
 add_subdirectory( src/ACEtk/Table/Data/test )
-add_subdirectory( src/ACEtk/Table/Header/String/test )
 add_subdirectory( src/ACEtk/Table/Header/test )
 add_subdirectory( src/ACEtk/Table/test )
 add_subdirectory( src/ACEtk/ContinuousEnergyTable/test )
 
@@ -177,21 +177,6 @@ void wrapContinuousEnergyTable( python::module& module, python::module& ) {
     "principal_cross_section_block",
     &Table::principalCrossSectionBlock,
     "The principal cross section block"
-  )
-  //! @todo solve the header version print issue to add this to the table definitions instead
-  .def(
-
-    "to_file",
-    [] ( const Table& self, const std::string& filename ) {
-
-      std::ofstream out( filename );
-      self.print< 1, 0, 0 >( out );
-      out.close();
-    },
-    "Write the ACE table to a file\n\n"
-    "Arguments:\n"
-    "    self        the table\n"
-    "    filename    the file name and path"
   );
 
   // add standard block definitions
 
@@ -73,7 +73,7 @@ void wrapTable( python::module& module, python::module& ) {
     [] ( const Component& self, const std::string& filename ) {
 
       std::ofstream out( filename );
-      self.print< 1,0,0 >( out );
+      self.print( out );
       out.close();
     },
     "Write the ACE table to a file\n\n"
@@ -102,7 +102,7 @@ void wrapTable( python::module& module, python::module& ) {
     [] ( const Component& self ) {
 
       std::ostringstream out;
-      self.print< 1,0,0 >( out );
+      self.print( out );
       return out.str();
     },
     "Return the string representation of the ACE table"
 
@@ -48,6 +48,20 @@ void addStandardTableDefinitions( PythonClass& table ) {
     "table\n\n"
     "Arguments:\n"
     "    filename    the file name and path"
+  )
+  .def(
+
+    "to_file",
+    [] ( const Table& self, const std::string& filename ) {
+
+      std::ofstream out( filename );
+      self.print( out );
+      out.close();
+    },
+    "Write the ACE table to a file\n\n"
+    "Arguments:\n"
+    "    self        the table\n"
+    "    filename    the file name and path"
   );
 }
 
 
@@ -1,6 +1,5 @@
      2.0.1      92235.710nc              ENDFB-VII.1
-  233.024800   2.5301E-08 2012-12-19    3
-The next two lines are the first two lines of 'old-style' ACE.
+  233.024800   2.5301E-08 2012-12-19    2
  92235.80c  233.024800  2.5301E-08   12/19/12
 U235 ENDF71x (jlconlin)  Ref. see jlconlin (ref 09/10/2012  10:00:53)    mat9228
       0         0.      0         0.      0         0.      0         0.
 
@@ -2,6 +2,7 @@
 #define NJOY_ACETK_TABLE
 
 // system includes
+#include <cctype>
 #include <istream>
 #include <regex>
 #include <string>
 
@@ -1,41 +1,94 @@
+/**
+ *  @class
+ *  @brief The header information in an ACE file
+ *
+ *  There are multiple version of the header.
+ *
+ *  The 1.0.0 (or legacy header) contains the following information:
+ *    - line 1: ZAID, AW (atomic mass ratio), TZ (temperature in MeV), date
+ *    - line 2: description (70 characters), material identifier (10 characters)
+ *
+ *  The 2.0.0 and 2.0.1 header contains the following information:
+ *    - line 1: VERS (header version), SZAID, SRC (evaluation source)
+ *    - line 2: AW (atomic mass ratio), TZ (temperature in MeV), date, N (comments)
+ *    - line 3 to N+2: comment lines (this is often 2 lines for the 1.0.0
+ *      header but that is not guaranteed)
+ *
+ *  Some ACE files with 2.0.x headers also seem to have some formatting issues
+ *  where the data is shifted by a column.
+ */
 class Header {
-public:
-  #include "ACEtk/Table/Header/String.hpp"
 
-  /* convenience typedefs */
-  using Comment = String<70>;
-  using SZAID = String<24, true>;
-  
   /* fields */
-  year_month_day                  processDate;
-  Quantity< Mega<ElectronVolts> > processTemperature;
-  double                          atomicWeightRatio;
-  SZAID                           szaid;
-  std::vector< Comment >          comments;
-
-protected:
-  using MAT = String<10, true>;
-  using Source = String<24>;
-
-  template< int... values >
-  using Version = std::integer_sequence< int, values... > ;
-  
-  std::optional< MAT > mat;
-  std::optional< Source > source;
+  std::string zaid_;
+  double temp_;
+  double awr_;
+  std::string date_;
+  std::vector< std::string > comments_;
+
+  /* auxiliary functions */
+  static std::string strip( const std::string& string ) {
+
+    std::string result = string;
+    auto notspace = [] ( char c )  { return !std::isspace( c ); };
+
+    auto front = std::find_if( result.begin(), result.end(), notspace );
+    result.erase( result.begin(), front );
+    auto back = std::find_if( result.rbegin(), result.rend(), notspace );
+    result.erase( back.base(), result.end() );
+    return result;
+  }
+
+  static std::string left( const std::string& string, std::size_t length ) {
+
+    std::string result = string;
+    result.resize( length, ' ' );
+    return result;
+  }
+
+  static std::string right( const std::string& string, std::size_t length ) {
+
+    std::string result = string;
+    const auto pivot = result.size();
+    left( result, length );
+    std::rotate( result.begin(),
+                 std::next( result.begin(), pivot ),
+                 result.end() );
+    return result;
+  }
 
 public:
-  Header( year_month_day processDate,
-	  Quantity< Mega<ElectronVolts> > processTemperature,
-	  double atomicWeightRatio,
-	  SZAID&& szaid,
-	  std::vector< Comment >&& comments ) :
-    processDate( processDate ),
-    processTemperature( processTemperature ),
-    atomicWeightRatio( atomicWeightRatio ),
-    szaid( std::move(szaid) ),
-    comments( std::move(comments) ){}
-  
-  /* static methods */  
-  #include "ACEtk/Table/Header/src/parse.hpp"
+
+  Header( const Header& ) = default;
+  Header( Header&& ) = default;
+
+  Header( const std::string& zaid, double awr, double temperature,
+          const std::string& date, const std::string& title,
+          const std::string& material ) :
+    zaid_( strip( zaid ) ), awr_( awr ), temp_( temperature ),
+    date_( strip( date ) ),
+    comments_( { left( title, 70 ) + right( material, 10 ) } ) {}
+
+  /**
+   *  @brief Constructor (from a buffer)
+   *
+   *  @tparam Iterator   a buffer iterator
+   *
+   *  @param[in] state   the buffer state
+   */
+  template< typename Iterator >
+  Header( State< Iterator >& state )
+    try : Header( parse( state ) ) {}
+    catch( std::exception& e ) {
+
+      Log::info("Error while constructing ACE Table Header");
+      throw e;
+    }
+
+  /* static methods */
   #include "ACEtk/Table/Header/src/print.hpp"
+
+private:
+
+  #include "ACEtk/Table/Header/src/parse.hpp"
 };