The recruiter will clandestinely contact on-target people who have the right background for the role. They’ll tell the candidate that the job is confidential and the applicant needs to keep the information to themselves. If the executive recruiter has a solid reputation, the person will understand and comply. There will be some people who feel uncomfortable and politely bow out of contention.
To save money from not using the services of a recruiter and demonstrating that the current employees get the first crack at newly opened internal jobs, human resources will first look for talented insiders. The company won’t place an ad for this job, as they want to focus on the people who already work at the organization.
Another similar example is when a new role is created, but the company feels that no one within the unit possesses sufficient skills to get the promotion. The business will want to keep recruitment a secret so as not to invoke the ire of the team. If the workers recognize the job description, employees will angrily confront their boss, demanding to know why they weren't even offered an interview and went straight to finding an outsider.