The Boston Globe gives a tutorial on royal titles. This won't come up for most editors, but it's interesting reading for the dedicated nonetheless.

The men are Sir Mick and Sir Paul and Sir Elton, not because they think it's all a lark (though they may), but because "Sir Firstname" is the proper short form. (Around the table at Camelot, you never heard Sir Lancelot referred to as Sir du Lac.)

And don't even get hard-core British editors started on Princess Di. ...