In the About section on my Facebook page, they list my jobs:
I am being harassed by a blue triangle to add a city to one of my past jobs.
I am disallowed from disclosing that information. When I try to write something like "Classified" or "Nope" it won't let me save it. It requires an actual city. I would prefer not to simply lie about the city.
Anybody know how to get Facebook to leave me alone?
There are three ways to stop the "Add city to" notification from bothering you. You've already mentioned the first two.
The last is to simply remove the job from your profile.
Sure, it would make things a little harder for people stalking you if you leave holes in your history, but Facebook is not a CV or resumé, so there's no harm in dropping things here and there.
To make things easier still, remove all your job history entirely, leaving that information only for your CV or resumé.
