What I know as a (retired) attorney is that the law about what is required with respect to a valid will varies from state to state.

So if you're crafting a do-it-yourself will with the use of the internet and/or books you've definitely got to pay attention to that.

My advise is to hire a good lawyer who is familiar with the requirements of your state.

And you raise a good point about jurisdictions that require that a will be registered and thus become a public.