how did ac3d know i was working on a plane?

[Michael Wilson]

i added ATTR_shiny_rat 0.8 under the first line in the object file using a text editor, to make the fuselage shiny.

next i added 3 small air intakes to the nose. then i saved that and exported to object file. i noticed the ATTR_shiny_rat 0.8 was gone (which is ok with me if its necessary to re-write it each time) but what i dont understand is that it was replaced with the word "cockpit_region" ...how did ac3d know that i was working on a plane? ...i could have been making a car... i searched in the hierarchy and couldnt find anything with the word "cockpit".


here is the ac3d file and object file:
http://forjets.netfirms.com/z_tristar.zip



and here is the top few lins of what it says:


I
800
OBJ

TEXTURE fuse.png
COCKPIT_REGION 0 0 2048 1024
POINT_COUNTS 33262 0 0 107544
VT -1.888565 -1.435135 4.162186 0.713898 0.687515 0.132965 0.098495 0.581009
VT -1.607742 -1.724289 4.149582 0.713898 0.687515 0.132965 0.098053 0.573395
VT -1.920258 -1.484406 4.587143 0.713898 0.687515 0.132965 0.113251 0.579712