Skitt's law

Muphry's law is an adage that states: "If you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written." The name is a deliberate misspelling of Murphy's law.

Similar laws have also been coined, usually in the context of online communication, under names including Umhoefer's Rule (or Umhöfer's Rule), Skitt's Law, Hartman's Law of Prescriptivist Retaliation (or The Law of Prescriptive Retaliation), The Iron Law of Nitpicking,McKean's Law, and Bell's First Law of USENET. Further variations state that flaws in a printed or published work will only be discovered after it is printed and not during proofreading, and flaws such as spelling errors in a sent email will be discovered by the sender only during rereading from the "Sent" box.

John Bangsund of the Society of Editors (Victoria) in Australia identified Muphry's law as "the editorial application of the better-known Murphy's law" and set it down in 1992 in the Society of Editors Newsletter.

The law, as set out by Bangsund, states that:

(a) if you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written;
(b) if an author thanks you in a book for your editing or proofreading, there will be mistakes in the book;
(c) the stronger the sentiment expressed in (a) and (b), the greater the fault;
(d) any book devoted to editing or style will be internally inconsistent.

It goes on to say:

Muphry's Law also dictates that, if a mistake is as plain as the nose on your face, everyone can see it but you. Your readers will always notice errors in a title, in headings, in the first paragraph of anything, and in the top lines of a new page. These are the very places where authors, editors and proofreaders are most likely to make mistakes.

Bangsund's formulation was not the first to express the general sentiment that editorial criticism or advice usually contains writing errors of its own. In 1989, Paul Dickson credited editor Joseph A. Umhoefer with the adage, "Articles on writing are themselves badly written", and quoted a correspondent who observed that Umhoefer "was probably the first to phrase it so publicly; however, many others must have thought of it long ago." An even earlier reference to the idea, though not phrased as an adage, appears in a 1909 book on writing by Ambrose Bierce:

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