Peggy came running around the table. “Somebody left these pennies
and quarters on the table,” she exclaimed as she handed them to me.
There were two pennies and, folded up, two dollar bills. So Peggy
knows two coin names and knows that both coins and specie can be
money. she has (as frequently witnessed in reference to coins) applied
“penny” as a label for any coin. she has chosen to apply “quarter” as a
different money name to another kind of money, i.e. currency.
Beautiful thinking, accidentally wrong.

The interesting problem this highlights is that the processes of
generalization and specification are much more complex than attaching
labels at the right description level and then extending them. There are
problems of shifting labels as classification refinements are developed.