It appears completely silly or stupid to me.
As if someone would put that on LinkedIn. Or anywhere else outside the pages of a biography.
I know people with security clearances, and I know people who do this, and people who don’t do this.
There is a difference. The former is an @$$hat.
actually no ... for certain positions in aerospace and defense manufacturing you’re required to have certain clearances. I had TS+ when I was a naval officer but didn’t have a reason to maintain since I got out... now I have a hard time applying to jobs in defense/aerospace because no one wants to pay for the investigation to update my clearances and I can’t do it myself.