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 [![License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat)](http://opensource.org/licenses/MIT)
 
 ## Introduction
-xlnt is a C++14 library for reading, writing, and modifying XLSX files as described in [ECMA 376](http://www.ecma-international.org/publications/standards/Ecma-376.htm). The API is based on [openpyxl](https://bitbucket.org/openpyxl/openpyxl), a Python library to read/write Excel 2007 xlsx/xlsm files, and ultimately on [PHPExcel](https://github.com/PHPOffice/PHPExcel), pure PHP library for reading and writing spreadsheet files upon which openpyxl was based. This project is still very much a work in progress, but the core development work is complete.
+xlnt is a C++14 library for reading, writing, and modifying XLSX files as described in [ECMA 376 4th edition](http://www.ecma-international.org/publications/standards/Ecma-376.htm). The API is based on [openpyxl](https://bitbucket.org/openpyxl/openpyxl), a Python library to read/write Excel 2007 xlsx/xlsm files, and ultimately on [PHPExcel](https://github.com/PHPOffice/PHPExcel), pure PHP library for reading and writing spreadsheet files upon which openpyxl was based. This project is still very much a work in progress, but the core development work is complete.
 
 ## Usage
 Including xlnt in your project