In linguistics, and more specifically pragmatics and discourse analysis, we identify maxims of conversation: the (usually) unwritten, subconscious rules that govern how people talk to each other, and what constitutes cooperative (or "polite") conversation.

As the term maxim implies, a maxim of conversation is basically a command. Grice popularized the term with his five maxims of polite conversation, but it was quickly realized that his maxims (the maxims of quality, quantity, relevance and manner,) were not universal.
For example, in Mexico the maxim of quality is superceded by the maxim of "give some answer". Typically, if you ask someone for directions to the post office, they will tell you something, even if they don't know where it is (though if they do know, the maxim of quality instructs them to give you that information). So, different speech communities have different maxims, and their identification and comparison is an important part of understanding a language's/community's discourse.

Maxims can be used in three basic ways:
1. Exploit - to exploit a maxim is to follow it. If the maxim is, "Give some answer to answer to a question, even if it isn't true," you do so.
2. Flout - to go against the command of a maxim in order to achieve a certain end, which is understood by the listener (see flout for more information on this often difficult to understand distinction.)
3. Violate - to go against a maxim, causing communicational breakdown. The maxim says, "Give some answer to a question, even if it isn't true," and you say, "I'm sorry, but I don't know where it is," (or, "Lo siento, pero no sé donde está ese lago.")

An anecdote told to me by my advisor illustrates the distinction between a flout and a violation well:
My advisor's friend went out to dinner at a sushi restaurant with her sister, who was visiting from Washington, D.C.. On the plate of sushi, as is customary, there was a little hunk of wasabi. The sister pointed to the wasabi and said, "What is that?" Now, my advisor's friend knew that there are sushi restaurants in Washington, and figured that her sister must have had Japanese food at some point in her life before, so she said, "It's guacamole." So her sister put the whole chunk into her mouth. When she recovered, she was very angry at having been lied to. My advisor's friend had intended to flout the maxim of quality - thinking her sister would get it (especially because guacamole would be such an unlikely thing to find in japanese food,) but because the conversational jump was not made, and in fact conversational breakdown occured, the maxim was violated.