The Drawing Exchange Format (DXF) from AutoDesk is a verbose ASCII geometry format capable of representing lines, simply defined surfaces, and polygons (3D faces).
The file structure of a DXF file is divided into 4 main sections:
Each section is preceded by a group code 0, followed by the SECTION string, a group code 2 and the type of section. A section is concluded with the 0 groupcode and the ENDSEC string. In each section, there are different items, each consisting of 2 lines: the first to declare the nature of the item, the second to define it's value. Each item in a DXF file takes a new line, therefore even the description of a simple vertex takes up to 12 lines.
The group codes (GC) defines the nature of the value on the next line. There are general and section specific group codes.