Have you gained any security clearances by government intelligence or law enforcement agencies? Don’t forget to list the clearances on the resume, even if they’re out of date. If they’ve lapsed, be sure to include the year that the clearance lapsed.
Why? The obvious reason is that some government employers require the clearances and lacking them can be a legitimate reason to not offer you an interview, if there are equally qualified job candidates who have already earned the clearances. Moreover, private employers may have government contracts or want to compete on government bids (whether you know about it or not), so they may favor job candidates whose resumes include the information.
Job seekers may not appreciate that Top Secret clearances may cost potential employers tens of thousands of dollars. If you have passed clearances for the first half of your life, then this could save the employer substantial money if you’re hired. And if you’re hired, having the clearance could be a reason for getting a promotion.
By the way, there are many security designations beyond Top Secret. If you have some of those, it usually isn’t necessary to list them unless the job application requires it. (If you’re not asked, don’t tell).