Muphry's Law

Yes, Muphry:

Muphry's Law is the editorial application of the better-known Murphy's Law. Muphry's Law dictates 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.