If a listing has a Hubbard Clause on it, the list agent has to go to Add/Edit and turn the Hubbard Clause on.
After you select Y in the Indicate if this listing is subject to a Hubbard Clause field, make sure to click Submit Listing.
The listing's status will not change- it remains in the Active status. You do not need to change it to Show in addition to turning on the Hubbard Clause.
There is a section in the upper right of the Full display that indicates if the listing has a Hubbard Clause on it:
Hubbard is technically not a status or change type, so you cannot search for Hubbard listings in the Status section. You would have to use the Additional fields section at the bottom of the search screen to add the Hubbard Y/N field.