Telephone companies refer to an entry in a telephone book as a “listing”.

Real-estate agents refer to an item in a list of for-sale properties as a “listing”.

But the noun “listing” describes the process of creating a list.

I wonder why such an entry in a list is not called a “listed” instead.

The word “listed” makes as much sense as the word “listing” to refer to an entry in a list.

Perhaps the use of “listing” in place of “listed” is consistent with my “Devolution toward Simpler” linguistic hypothesis.

After all, it is simpler to say “listing” than it is to say “listed”.