I was required similar things when I applied a volunteer job. But I forgot the exact name. They give me a form and ask me mail to police service, police will give you this information. It costs $16.00.
This information certifies you have good record in security. Some position needs this document
谁能告诉我这个"a security clearance at enhanced level"具体是什么意思？到哪里能办，还是必须是公民？这个PWGSC是什么部门？All positions require, at a minimum, a security clearance at enhanced level, issued by PWGSC.