Gamma settings ?
You've got it. Gamma can be a subtle characteristic. We figured you
didn't want your gamma changed by the simple act of loading a .prj
file (which you might have received from another person with totally
different system gamma settings). On the other hand, you want the
3ds.prj file to provide you with total customization. Thus, the
3ds.prj file carries system gamma settings, while all other .prj
files do not.
– Jack