is based on the XML format. Its main tasks are: precise display on a variety of devices, full preservation of document structure, ability to be transformed into other formats. Unlike other popular e-book formats, fb2 does not specify the appearance options for different devices’ displays. The format employs tools to indicate the different parts of the book – verses, epigraphs, quotations.
XLSX is a file format created with Microsoft Excel, version from 2007 and younger. This file is a spreadsheet. All data distributed document and stored in the cells. Each cell has a unique address, which is denoted by the letters and Arabic numerals. XLSX file format is based on the Open XML. To reduce the size of the file is compressed ZIP.