I write this documentation because I think, in my honest opinion, that the "official" reference is incomplete, often with errors or without descriptions, in particular the old references often change completely style and the new one presents much errors and deficiencies (for example it is since version u19.1.01 in February 2004 that Autodesk Inc. doesn't change the chapter "Revisions to the DXF Reference", and only in the version u15.0.02 this chapter is complete and correct).
I hope this work can help who wants to understand how to read and write a dxf, however for the moment this may not be a complete reference, only a "diff" reference.
Autodesk has recently released the latest reference of DXF files under Creative Commons Attribution-NonCommercial-ShareAlike (CC BY-NC-SA) 3.0 that is incompatible with FDL.
This is however an improvement regarding freedom of information about the DXF format.
I can make mistakes, if you see this or you have questions please contact me.
The author of this documentation is Paolo Caroni (me), but the files class.html, image.html and hatch.html was written by Bert Timmerman (the author of libDXF project), the file libdxf_main.html was written by me but it is only a translation in html from a txt file (written by Bert) with little changes.
AutoCAD is a trade mark registered by Autodesk Inc., all rights reserved, any reference to this software is random and for explanatory purposes only.
This documentation was released under the terms of the GNU FDL 1.3 or any later versions