lrf The LRF format is a proprietary format developed by Sony in collaboration with Canon, as a document and text encoding standard for the Broad Band eBook file format. The format specifically targeted Sony portable eBook readers and was capable of encoding both text, pagination, and images. Being unencrypted, LRF encoded files do not enforce DRM. This is in contrast to the LRX format which is also part of the BBeB eBook file format which does support encryption for DRM files. The Sony eBook store announced in July 2010 a discontinuation of support for the LRF format in favor of the public and open EPUB format.
fb2 The .fb2 filename extension refers to the open XML based eBook format known as FictionBook. The file format was developed by Dmitry Gribov with an initial release in 2004, quickly gaining popularity in Russia. The format is open which in this context means it has no compatibility with digital rights management technologies. The structure of the format splits the contents of the data into three sections; title information, XML document information, and finally information about the paper edition which is optional.