This was originally posted by ERO in the comments at Altered Carbon SEASON 01 , thought it would be helpful for the second season too so copy pasting shamelessly 😉
From Dippers to Needlecasting: Here’s Your Altered Carbon Glossary
653 – A proposed law that would allow the stacks of murder victims to be booted up to testify against their killers, even if they have Neo-C coding which wouldn’t allow them to be brought back in any way, shape or form because of religious beliefs. It’s a very controversial law and forms the ethical backbone of Altered Carbon.
Aerium – A city constructed high above the ground and in the clouds where only the wealthy Meths live in lavish mansions. It’s where Bancroft (James Purefoy) lives.
AI Hotel – A hotel run entirely by artificial intelligence, they aren’t exactly hotspots for tourists because they are known to become obsessed with and violently protective of their guests. Because of that, they’ve fallen out of favor of the living and are often empty. The AI character of Poe (Chris Conner) runs an Edgar Allen Poe-themed AI hotel in Altered Carbon. In the book, the hotel is Jimmi Hendrix-themed.
Construct – A virtual environment sometimes used for torture or therapy.
Cortical Stacks – Commonly referred to simply as “stacks” in the series. Stacks are disks inserted in the back of the neck that house the human consciousness. They can be moved from body to body — as you see with Takeshi Kovacs’ (Will Yun Lee) stack and Ryker’s (Joel Kinnaman) body — but if they’re damaged, then that’s it, the consciousness is dead. Really dead.
CTAC – Stands for Colonial Tactical Assault Corp; a Protectorate fighting force that quells rebellions. Think the grunts, cops or other law enforcement that work for the government. Kovacs was initially a member of CTAC before defecting to the Envoys.
DHF – Stands for Digital Human Freight; aka the coding that makes up a human consciousness. These go into stacks.
Dipper – Hackers, essentially. A dipper specializes in getting information from stacks, which can mean extracting memories or inserting new information into the stack.
Double-Sleeving – The extremely illegal practice of transferring a copy of your consciousness into a second sleeve, thereby making two versions of yourself. It sounds fun, but clearly results in some pretty tough decisions — and intense games of Rock, Paper, Scissors — as you’ll see by the end of Season 1.
Envoys – Rebels who developed heightened senses and reflexes. They sought to obliterate stack technology because of the inequality it was causing in society, but they were all eventually slaughtered by CTAC soldiers. Kovacs was an Envoy after he left CTAC, and the group was led by Quellcrist Falconer.
Grounders – The less wealthy members of society who live on the ground beneath Aerium.
Meth – Derived from the word “Methuselah” — the Biblical figure who lived for hundreds of years — a meth is a wealthy person who has essentially becomes immortal by constantly creating clones of themselves (meaning they never have to age) and backing up their consciousnesses to servers in case of stack damage. They kind of have their own society high up in the clouds.
Needlecast – Transferring DHF code remotely from one sleeve to another (or to another receiver). Think of it as using the Cloud, except for uploading your mind, man! Bancroft uses the tech to transmit his DHF to a satellite as a means of backup, in case he’s, uhh, murdered or something. The actual technology involves concentrating a signal into a specific beam, rather than a wider-reaching signal.
Neo-C – Neo-Catholicism; the belief that a human should have one life and one body and it is a sin to insert their stack into a new sleeve. The protests early in the series involve believers of Neo-Catholicism.
Neo-C coding – Coding on a person’s stack indicating their beliefs and making it illegal to spin them up.
Personality Frag – Short for “Personality Fragmentation.” This occurs when a stack has been dropped into too many different sleeves, causing insanity.
Protectorate – The military force of the UN, which keeps the peace between settled worlds.
Psychosurgery – Think of this as a form of therapy in a virtual environment. In Altered Carbon, it’s frequently used to help DHF code that’s been traumatized or emotionally corrupted due to a violent event.
Real Death – Critical damage to a stack, which ultimately destroys the consciousness it was housing. Lose your stack, lose everything. There’s no coming back from real death.
Reaper – A drug that simulates death. Rich people who have plenty of backup sleeves actually use it to experience the sensation of death. In small doses, it has other benefits including lowering your body temperature and a sense of eerie calmness, which is why some soldiers use it.
Simulspace – Virtual reality, basically. But because this is so far in the future, the “virtual” didn’t cut it since the tech gives the feeling of being incredibly real, there’s barely anything virtual about it.
Sleeve – What you put a stack into. Essentially a human body that can take a new stack. These can also be cloned bodies. Bancroft had several copies of himself. Rich people would often upgrade their stacks at great costs in an effort to live forever. Others are given whatever sleeves are lying around if their stacks are brought back.
Sleeve Sick – Disorientation that comes when your stack is inserted into a new sleeve. Pretty much everyone is messed up when they’re initially thrown into a new body. Even Kovacs has trouble with it in the first episode, probably because all of Ryker’s massive muscles need some time to get used to. Those stacks which went down in particularly violent fashion are especially prone to becoming sleeve sick.
Sleeve Death – When your body dies, but your stack remains intact allowing you to live on in another sleeve. Sleeve Death kind of changes the rules on mortality as some people don’t fear “death” or injury as they figure they can just be reincarnated in a new body.
Songspire – A weird and rare tree that emits pleasant fragrances and sounds. It’s not known what they really do, but Bancroft has one in his hallway, if that shows just how rich he is.
Spin Up – Putting the stack of a dead person into a new sleeve, allowing them to live again, even if only temporarily. We see this a few times in Season 1, often with hilariously results as certain stacks are put into mismatched bodies.
Synthetic Sleeve – A human body that has been made in a lab, they can be modified to have different abilities, most commonly a version of shapeshifting. One specific character shows off the particularly grotesque perks of a synth sleeve.