*Pragmatics is the context of the message – e.g. age of participants, relative status, locations, job, hobbies etc.
*Prosodic features – elements which mimic spoken language, e.g. sounds like: grr, urr (eurgh), er, mmm
*Idiolect – the distinctive way that an individual speaks (can be conveyed through styles used), bit like ‘tone of voice’
*Standard English vs Slang – slang is informal, colloquial words or phrases ‘wicked’ (good) or dialect ‘yarling’ northern dialect for ‘wailing’ (from Old Norse – as spoken by the Vikings), like Cockney rhyming slang.
*Jargon technical terms shared by set groups, often relevant to a job, hobby, or area of science/academic study, e.g. doctors, car mechanics, the church, the military, etc. Allows precise, clear communication.
*Formal/Informal register (tone) can be patronising, friendly, intimate, ironic, over-friendly, formal, distant, etc.
Emoticons (;-) 😉 ;-o ;-s  xoxox  and x – number of xxx also significant. This is a ‘text version’ of the *paralinguistic features of speech like facial expressions, tone of voice. Emoticons are used to make sure mood (or tone) is clear.
Asterisks [*] can be used to show gesture *cringe* 
Ellipsis … can create a pause for comic effect or to create suspense, mimicking the style of speech
Emphatic doubling (or tripling) of letters creates a prosodic effect, e.g.  ‘sooo’, see also !!!!                                                                                            CAPITALS/Capitalization used for EMPHASIS

*Back-channelling – giving feedback to show that the message is understood
*Turn-taking Notice how participants 1. Ask questions for a. information b. social bonding purposes 2. Seek clarification 3. Volunteer interesting information (gossip)  4. Ask further (often social bonding) questions to prolong the interaction 5. Echo the other speaker, to show/create cohesion (bonding)
*Instant feedback texting can be instant– though messages aren’t always answered immediately.
*Exclamations/interjections Never! Noooo! (incl OMG and LOL). These convey reactions to information given, conveying surprise, shock etc or showing that you ‘get it’. This can be a form of back-channelling.
*Overlap (synchrotexting) is where turn-taking goes wrong, and both participants message at the same time. This is more common on BBM and other IM services than in standard texting.

*Elliptical expression –missing out words from a sentence, e.g. haven’t seen you for time (this is also slang)
*Contractions e.g. cause (for because)
Unusual spellings acc (actually), hun (honey), luv (love), ta (thanks), probs (for probably)
*Elision  – blending two words together, e.g. inoo (I know) wassup (what’s up) howzat? (how’s that?) dunno, gonna. To some people these are cringeworthy (ditto logograms and initialisms). To others, they are essential.
Initialisms OMG (oh my god) LOL (laugh out loud), btw (by the way), WTF and OFFS (avoids actually swearing) etc
Logograms  l8r b4 wuu2 (what you up to) (increases speed of texting, especially on a non-smartphone)
Acronyms FB (facebook) pp (parish priest) etc AND OTHER SHARED reference points, or assumptions, such as ‘you know that 6th former… well he’s on my bus!!!’ (We don’t know who she’s talking about, but the other girl does).
*Subtext the hidden meaning to the conversation, i.e. the part of the meaning that the texters don’t need to explain, i.e. shared knowledge, assumptions / or are trying to keep hidden (socially awkward elements are politely hidden)

*Expected greeting: people usually open with ‘Hi’ or ‘Hello’. Comment on what text uses instead of the expected greeting as an opener.                                     
*Expected Sign off i.e. ‘bye’, ‘see you later’, ‘X’ etc
*Downplays, weakens – texters often need to work hard to make sure they don’t cause offence. So they may want to downplay or weaken a statement with an emoticon, humour or a qualifying statement.
*Repetition as always is worth commenting on. Usually it is used for emphasis, but also note repetition between texters as a form of back-channelling