Ketchup
No one likes to work at an office that smells like ketchup, we can all relate to that, but I’m sorry, this is not being passive-aggressive, rather straight out telling people to throw away their stinky left-overs. The answer, though, is priceless. Smelly, but priceless. The ketchup-eating person probably didn’t appreciate this note one bit.
If they sent out an e-mail instead of putting up a sign, no one would’ve been able to answer them with ketchup, forcing them to take down the sign. Just saying. It’s the year 2020, people, we’ve said it once and we’ll say it again – let’s be environmental, stop wasting paper and start sending out emails. Don’t worry, you can be passive-aggressive online as well.