The sections can be in any order in the file, but only one section of each type is permitted.
Objects have material, lighting and vertex attributes.
The periods after the XX and YY codes are necessary, even if the 'z' string is non-existent. EN END End of rendering list. Each list MUST end with this object. LI LINE Treat the first two vertexes as endpoints of a 3D line. ME MESH Treat the three vertexes as the corners of a 3D triangle.