The clipboard is an easy way to see all the requests your workers have (that are not being fulfilled by a Courier).
Using the Clipboard
When you first make the clipboard and right-click anywhere, you will get a message to sneak + right-click on the Town Hall to register the clipboard.
After you register the clipboard, this message will appear:
Now when you right-click while holding the clipboard, you will see all your citizens’ requests on the clipboard (that are not being fulfilled by a Courier)!
If you click on the exclamation mark in the top right, you will only see requests for things that workers need right now.