There's the little bug stopping by for a drink. :-)
From looking at an old list of Commands, it might've been version 8 Beta; that's when we got Environments and Luminances. I remember downloading V8 Beta at the local community college (fast T1 line), then 9/11 hit. Versions 6 & 7 just had Materials.
Designer, Deluxe, (Basic, Expert, Professional), Platinum
Windows 10 Pro (1909), 64-bit