[1] Forms of rudeness include behaving in ways that are inconsiderate, insensitive, deliberately offensive, impolite, obscene, or that violate taboos.
In many cultures, joking can create a context where rudeness is temporarily excused or indulged for the purpose of making people laugh.
By contrast, in the modern era, greeting a friend by name while he is wearing a mask, or talking to them later about their costume or activities, is not generally regarded as rude.
Robin Lakoff addressed what she named strategic rudeness, a style of communication used by prosecutors and therapists (attack therapy) to force their interlocutors (a courtroom defendant or patient) to talk or react in a certain way.
In most modern cultures, insulting a person or group of people, especially for any reason outside their immediate control, such as having a medical condition, being a particular gender, or being poor, is considered rude.
Failing to speak can also be rude: a rude person might pointedly ignore a legitimate and polite greeting or question to communicate disregard for the other person,[2] or might fail to express appropriate thanks for favors or gifts by way of communicating either a sense of selfish entitlement or a disregard for the efforts of the giver.
For example, some black communities in the United States use The Dozens as a mechanism to promote verbal abuse resilience and maturity among young people.
[2] C. S. Lewis writes that "A girl in the Pacific islands wearing hardly any clothes and a Victorian lady completely covered in clothes might both be equally 'modest,' proper, or decent, according to the standards of their own societies"—but that in each culture, the idea of immodest, improper, and indecent dress existed, and that violating the culture's standard was rude.
Similarly, poor table manners can disturb or disgust nearby people, as can yawning, coughing, farting or sneezing without covering the mouth.
In extreme cases, this can escalate to the complete and deliberate social exclusion of the disrespected person; in others, the rudeness is only temporary and may be unintentional.
For example, it can be rude to use electronic devices, such as mobile phones, if this results in ignoring someone or otherwise indicating that the present company is less interesting or important than the people elsewhere or the text messages they send.