Can I record a private note about a candidate as well as their current salary, but not let the rest of the team see it?

Yes. Only Job Admins and Site Admins with the permission Can see private notes, salary info, manage offers, and approve jobs/offers can access the Private tab located on each candidate’s profile page, making this an ideal location to store sensitive candidate information.

The Private tab includes a place to record private notes, as well as salary details via private custom candidate fields.