Mr. D-- asks a question

In Chapter 5 of Susanna Clarke's Jonathan Strange & Mr Norrell (specifically, on Page 54 of the U.S. hardcover), is this paragraph:

"You will not regret it, my dear sir!" cried Drawlight, "for three weeks ago I chose a set for the Duchess of B-- and she declared the moment she saw it that she never in her life saw anything half so charming!"

Eliding the name of a person or place, like the Duchess of B-- above, used to be commonplace in English-language fiction, and still is among writers going for a 19th-century effect. It lends an air of verisimilitude, as if the true identity of the real-life Duchess of B-- must be protected. But what is such an elision called? Anyone? Anyone? Bueller?