FISH is a slippery category-word. In modern biology, a fish is typically described as an aquatic, gill-bearing vertebrate with fins, and without limbs with digits. Fish are also a cultural symbol that can mean abundance, mystery, silence, or “life under the surface”, depending on which story a culture is telling about water, sea-travel, and the unknown.
# Fish in Hitchhiker’s Guide The most literal “fish” in Hitchhiker lore is the Babel Fish, a small creature you put in your ear so you can understand any language, and it becomes a running symbol of translation, misunderstanding, and how “perfect communication” can still produce perfect conflict
That phrase is not only a meme-line: it is literally a dolphin “parting gift” message in the story-world, and it becomes the title of the fourth book, which makes it a structural hinge in the series rather than just a punchline - wikipedia.org 
# FISH as a Hitchhiker identity In our Hitchhiker system, FISH is an acronym for “Fully Integrated Self-sovereign Humans”, and it is intentionally not a description of animals, and not a wink toward “AI fish”, and not a marketing word for “anyone with an account”. FISH means the credential-holder is a human being, and the identity is self-sovereign, and the whole point is that political standing inside the Hitchhiker commons is attached to humans only, not bots, not corporate agents, not simulated persons, and not ambiguous non-human actors. “Fully Integrated” means the identity is designed to work across the whole Hitchhiker stack, rather than being a single-site login: it is meant to be recognisable in community governance, access control, reputation, and rights-bearing participation in whatever the Hitchhiker network is building. “Self-sovereign” means the person controls the credential and the way it is presented, rather than outsourcing their personhood to a platform, and this is where Self-Sovereign Identity meets Hitchhiker culture: portable proofs, user-controlled disclosure, and a refusal to confuse “account” with “citizenship”. So the acronym is deliberately blunt: FISH draws a hard boundary around who counts as a political subject in the Hitchhiker world, and it does it with a silly word so you remember that the boundary exists.
# Related pages - Hitchhiker Passport. - Self-Sovereign Identity. - Proof of Humanity.