[awillen]

The dates and signatures bit is nonsense, but it does help to have things in writing to ensure everyone's on the same page. That just means that when you're discussing things not in writing, you send a written follow up to everyone that's involved immediately afterwards. If it's a meeting, take detailed notes and send them around afterwards. If it's a one on one conversation, just send a follow up email that says something like, "Hi x, I just wanted to memorialize our conversation - here are the main notes that I took. Please let me know if any of this sounds off to you. Thank you."

That doesn't preclude them from not reading that email and later telling you they said something completely different, but at that point you should probably be heading for the door anyway.