The security screening procedure introduced in Great Britain in 1950 to prevent political extremists and other unsuitable candidates from gaining access to sensitive posts in the British government. The PV consists of a questionnaire, an interview, and field inquiries conducted to verify referees. For applicants to posts in the security and intelligence services, Enhanced Positive Vetting requires an applicant for a security clearance to be supported by additional referees.
The PV process is a development of Negative Vetting, which is limited to checks conducted on the MI5 indices and the Criminal Records Office to establish whether any adverse information has been recorded. In the absence of such material, the applicant is cleared automatically.