In 1992 John Bangsund writing in the Victorian Society of Editors' Newsletter observed that Muphry's Law referred to the well-known editorial phenomenon that:

1. If you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written.
2. If an author thanks you in a book for your editing or proofreading, there will be mistakes in the book.
3. The stronger the sentiment expressed in (1) and (2), the greater the fault.
4. any book devoted to editing or style will be internally inconsistent.

Bangsund also notes that "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."

The name "Muphry" of course is a deliberate misspelling of the better known Murphy's Law. Muphry's law is closely related in spirit to Hartman's Law of Prescriptivist Retaliation: "any article or statement about correct grammar, punctuation, or spelling is bound to contain at least one error." We have, thanks to a prolific UseNet poster, an online version known as Skitt's Law. One G. Bryan Lord, using the nick Perchprism, responds to another user Skitt in an October 1998 post to alt.usage.english. Here is the Internet version is known as "Skitt's Law": roughly (it depends on which instance you wish to cite):

The point of laws like these is that everyone makes tyops typos.