If you open it, close it.
If you turn it on, turn it off.
If you unlock it, lock it up.
If you break it, admit it.
If you can't fix it, call in someone who can.
If you borrow it, return it.
If you value it, take care of it.
If you make a mess, clean it up.
If you move it, put it back.
If it belongs to someone else and you want to use it, get permission.
If you don't know how to operate it, leave it alone.
If it's none of your business, don't ask questions.
If it ain't broke, don't fix it.
If it will brighten someone's day, say it.
If it will tarnish someone's reputation, keep it to yourself.