>> And do you think the fact that John likes lemonade should be described by other facts in the database <<

How about a list of beverages, with the value Lemonade in it? That
would be nominal scale and not a flag. When we decide to research
other beverages, we extend the scale. Unlike a flag, I can ask how
much of a given beverage he drinks.

I extrapolate that if John drinks s certain number of Cokes and is of
a certain age, then I stand an 85% chance of selling him Pepsi (i.e.
kids the sweeter Pepsi to Coke). You cannot get that kind of
information from flags.

> How about a list of beverages, with the value Lemonade in it?

As I have asked several times already, what if they are only interested in
lemonade? Why should they bother with a list?

Anyway, you are still clearly either missing the point or intentionally
disregarding it. This is not about lemonade; this is about the fact that
some things are just yes/no indicators on their own, without "help" from
other facts. If you don't get it, you don't get it, and I'm afraid I can't
help to educate you any further. :-(