• Degree Modifiers
• Euphemism
• Innuendo
• Never Say "Die": Euphemisms for Death
• Nonverbal Communication
• Politeness Strategies
• Rhetorical Questions
• What Are Weasel Words?
• Whimperative

Examples and Observations:

• "The intention to communicate indirectly is reflected in the form of an utterance. Indirectness may (depending on its form) express avoidance of a confrontational speech act (say, an imperative like 'Go home!') in favor of a less intrusive form like a question ('Why don't you go home?'); or avoidance of the semantic content of the utterance itself ('Go home!' being replaced by an imperative that makes its point more circumspectly, like 'Be sure and close the door behind you when you leave'; or both ('Why don't you take these flowers to your mother on your way home?'). It is possible to be indirect in several ways and to various degrees."
  (Robin Tolmach Lakoff, "The Triangle of Linguistic Structure." A Cultural Approach to Interpersonal Communication: Essential Readings, ed. by Leila Monaghan, Jane E. Goodman, and Jennifer Meta Robinson. Wiley-Blackwell, 2012)

• Language-Related Cultural Themes
  "Where directness or indirectness are cultural themes, they are always language-related. As defined in speech-act theory, direct acts are those where surface form matches interactional function, as 'Be quiet!' used as a command, versus an indirect 'It's getting noisy in here' or 'I can't hear myself think,' but other units of communication must also be considered.
  
  "Indirectness may be reflected in routines for offering and refusing or accepting gifts or food, for instance. . . . Visitors from the Middle East and Asia have reported going hungry in England and the United States because of a misunderstanding of this message; when offered food, many have politely refused rather than accept directly, and it was not offered again."
  (Muriel Saville-Troike, The Ethnography of Communication: An Introduction. Wiley, 2008)
• Speakers and Listeners
  "Besides referring to how a speaker conveys a message, indirectness also affects how a listener interprets the messages of others. For example, a listener can infer a meaning that goes beyond what is explicitly stated, which can be independent of whether the speaker intends to be direct or indirect."
  (Jeffrey Sanchez-Burks, "Protestant Relational Ideology: The Cognitive Underpinnings and Organizational Implications of an American Anomaly." Innovations in Adolescent Substance Abuse Interventions, ed. by Eric Wagner and Holly Waldron. Elsevier, 2005)
• The Importance of Context
  "We sometimes speak indirectly; that is, we sometimes intend to perform one communicative act by means of performing another communicative act. For example, it would be quite natural to say My car has a flat tire to a gas station attendant, with the intention that he repair the tire: in this case we are requesting the hearer to do something. . . . How does a hearer know if a speaker is speaking indirectly as well as directly? [T]he answer is contextual appropriateness. In the above case, it would be contextually inappropriate to be only reporting a flat tire at a gas station. In contrast, if a police officer asks why a motorist's car is illegally parked, a simple report of a flat tire would be a contextually appropriate response. In the latter circumstance, the hearer (the police officer) would certainly not take the speaker's words as a request to fix the tire. . . . A speaker can use the very same sentence to convey quite different messages depending on the context. This is the problem of indirection."
  (Adrian Akmajian, et al., Linguistics: An Introduction to Language and Communication, 5th ed. MIT Press, 2001)
• The Importance of Culture
  "It is possible that indirectness is used more in societies which are, or which have been until recently, heavily hierarchical in structure. If you want to avoid giving offence to people in authority over you, or if you want to avoid intimidating people lower in the social hierarchy than yourself, then indirectness may be an important strategy. It is possible, too, that the more frequent use by women in western societies of indirectness in conversation is due to the fact that women have traditionally had less power in these societies."
  (Peter Trudgill, Sociolinguistics: An Introduction to Language and Society, 4th ed. Penguin, 2000)
• Gender Issues: Directness and Indirectness in the Workplace
  "Directness and indirectness are encoded by linguistic features and enact competitive and cooperative meanings respectively. Men tend to use more features associated with directness, which inhibits contributions from other speakers. Indirectness strategies encode collaboration and their use encourages others' voices into the discourse. Some linguistic forms that encode inclusiveness and collaboration are inclusive pronouns ('we,' 'us,' let's,' 'shall we'), modal verbs ('could,' 'might,' 'may'), and modalizers ('perhaps,' 'maybe'). Directness involves egocentric pronouns ('I,' 'me'), and absence of modalizers. Indirectness strategies are common in all-female talk when the talk encodes meanings of collaboration and cooperation. These features, however, are routinely denigrated in many workplace and business settings. For instance, a female manager in banking who modalizes and uses inclusiveness strategies, beginning a proposal with 'I think maybe we should consider . . .' is challenged by a man saying 'Do you know or don't you?' Another woman commences her recommendation in an academic meeting with 'Perhaps it would be a good idea if we thought about doing . . . ' and is interrupted by a man who says 'Can you get to the point? Is it possible for you to do that?' (Peck, 2005b). . . . Women appear to internalize male constructions of their performances and describe their communication strategies in business settings as 'unclear,' and 'vague' and say that they 'don't get to the point' (Peck 2005b)."
  (Jennifer J. Peck, "Women and Promotion: The Influence of Communication Style." Gender And Communication at Work, ed. by Mary Barrett and Marilyn J. Davidson. Ashgate, 2006)
• Benefits of Indirectness
  - "[George P.] Lakoff identifies two benefits of indirectness: defensiveness and rapport. Defensiveness refers to a speaker's preference not to go on record with an idea in order to be able to disclaim, rescind, or modify it if it does not meet with a positive response. The rapport benefit of indirectness results from the pleasant experience of getting one's way not because one demanded it (power) but because the other person wanted the same thing (solidarity). Many researchers have focused on the defensive or power benefit of indirectness and ignored the payoff in rapport or solidarity."
  (Deborah Tannen, Gender and Discourse. Oxford University Press, 1994)
  
  - "The payoffs of indirectness in rapport and self-defense correspond to the two basic dynamics that motivate communication: the coexisting and conflicting human needs for involvement and independence. Since any show of involvement is a threat to independence, and any show of independence is a threat to involvement, indirectness is the life raft of communication, a way to float on top of a situation instead of plunging in with nose pinched and coming up blinking.
  
  "Through indirectness, we give others an idea of what we have in mind, testing the interactional waters before committing too much--a natural way of balancing our needs with the needs of others. Rather than blurt out ideas and let them fall where they may, we send out feelers, get a sense of others' ideas and their potential reaction to ours, and shape our thoughts as we go."
  (Deborah Tannen, That's Not What I Meant!: How Conversational Style Makes or Breaks Relationships. William Morrow and Company, 1986)
• Multiple Subtopics and Fields of Study
  "'Indirectness' borders on and bleeds into many topics, including euphemism, circumlocution, metaphor, irony, repression, parapraxis. What is more, the topic . . . . has received attention in diverse fields, from linguistics to anthropology to rhetoric to communication studies. . . . [M]uch of the literature on 'indirectness' has remained in close orbit around speech-act theory, which has privileged reference and predication and has led to a narrow focus on pragmatic ambiguity (indirect performativity) in sentence-sized units."
  (Michael Lempert, "Indirectness." The Handbook of Intercultural Discourse and Communication, ed. by Christina Bratt Paulston, Scott F. Kiesling, and Elizabeth S. Rangel. Blackwell, 2012)