HEADER SectionΒΆ
In DXF R12 and prior the HEADER section was optional, but since DXF R13 the HEADER section is mandatory. The overall structure is:
0           <<< Begin HEADER section
SECTION
2
HEADER
9
$ACADVER    <<< Header variable items go here
1
AC1009
...
0
ENDSEC      <<< End HEADER section
A header variable has a name defined by a (9, Name) tag and following value tags.