John Gillingham once got into trouble when doing In Our Time on Radio 4 for calling King John "a shit".

That is both ingenious and desperate by Arnulf!

One reason for reissuing is presumably to link the previous grant to a new king and thus enhance the prestige/authority of the grant. Which also explains why no-one bothers forging charters by loser kings like Carloman.

Chicago Manual of Style has "personal communication" as a citation type, so you could adapt that: www.chicagomanualofstyle.org/tools_citati.... For magic eightballs, maybe have the manufacturer as corporate author?

If you are not sure how to cite your ouija board messages, here is a sample authority record for referring to the spirit of Princess Diana (lccn.loc.gov/n98096157)