If you unpack the exe (ahem!) and look at it under a HexEditor... So yes, BILLANDTED, SNOWFLAKES, ENTERPRISE etc... VERSIONNUM is also a code. That is still working. On the Xmas demos, they use v1.9 and the code SNOWFLAKES works, but in other builds, like 1.91, 1.92 while a code is in the Hex and Cheat activated is in the Hex, they don't work. So, I suspect, there is a code switch. So, when building the game it is 1 and 0 when retail.
With Holiday Lemmings 1993 v1.91, I think the exe was buggy and rather than fix the crash with -v -o, they disabled the enhanced bar in v1.92.
The only reason I would want the code to work, is if I make levels and want to test them. Thirty years, this year...