A misquotation is an accidental or intentional misrepresentation of a person's speech or writing, involving one or more of:

• Omission of important context: The context can be important for determining the overall argument the quoted person wanted to make, for seeing whether the quoted statement was restricted or even negated in this context, or for recognizing hints that it was meant as irony.
• Omission of important parts of the quote.
• Insertion of allegedly implied words or partial sentences: The inserted portions may be specially marked (e.g. by square brackets or cursive font). Using unmarked insertions is commonly deprecated. In order to constitute a misquotation, the implied portions must alter the meaning of the quote in a way that the original author did not obviously intend.
• Incorrect rephrasing: The quote is replaced by one which is only superficially identical in meaning, or one or more of the words in the quotation have been replaced by incorrect ones.
• Misattribution: Attributing someone else's (or no one's in particular) words to a person who did not use them. Misattribution is often found in satire.
• Misspelling, although usually inadvertent, can sometimes be used deliberately, especially with satirical intent, to portray the quoted person as stupid or uneducated.

The following causes are mostly responsible for misquotations:

• Imperfect reproduction, e.g. from memory, in communication or by transcription. Gossip, which involves many consecutive memorizations and mouth-to-mouth communications, can quickly 'mutate' a quote beyond recognition. In those cases, only the 'kernel' of the quote is held while the rest is omitted or simplified.
• Misunderstanding, if the person using the quote misjudges the importance of context, partial sentences, or inserts an invalid implication.
• Malice or deliberate deceit (Quote mining).
• Humor or satire.

• Actual quote uncertain. Variously, "If that guy has any way of making a mistake, he will" and "If there's more than one way to do a job, and one of those ways will result in disaster, then somebody will do it that way". Murphy's law has been purposely misrepresented and sometimes simply misinterpreted to mean "something will always go wrong" or "nothing will ever work perfectly". This is actually a statement of Sod's Law. Murphy's Law is really a design principle: if something can be done in more than one way (such as inserting a two-socket plug the wrong way around), somebody will eventually do it. The solution is to design defensively - if the plug is asymmetrical, it simply can't be plugged in the wrong way around. There is evidence that Murphy himself didn't mean it this way when he said it, for more details, read the complete article.