The example you give with the McDonalds/Burger King confusion boggles me. The way you write it seems to suggest to me that if you put the word's McDonalds on the note, but the addressee shows up at the Burger King, you are still somehow at fault for not communicating clearly. How could this possibly be the case? How far can you nail things down, in the end?

If you write "Went for a burger, meet me there!" and expect the other person to just infer that you meant McDonald's, you failed. Maybe you never eat at any other burger joint, and you assumed that your friend knew that, so that therefore they should have known where to meet you. Doesn't matter -- you failed to communicate what you meant; they didn't fail to understand what you wrote.