I thought this was a nice use of a sign. It's a big sticker affixed to a pothole on my street in Brooklyn. Well, more like a potcrater. It lets us know several things:
- Someone who can fix this knows about it
- Don't bother them because they already know about it
- You can rest assured something is happening
- If you want to let them know about more things like this there is a phone number
That it's attached to the thing it's informing on is key. There's no confusion about what the problem is, even though the sign doesn't say what it is they're "looking into." That allows the sign to be generic. NYC city services doesn't have to make a new sign for each problem. They just drive around with a stack of these stickers in their trunk.