# Zero Information Casualty

> Zero Information Casualty is both the endpoint of the Tyrer Accessibility Scale and the agent-first web standard, ZIC, built to reach it.

**Real.** This entry is about something real, written from outside the CharliVerse.

**Zero Information Casualty** means two linked things.

As a **condition**, it is the endpoint of the [Tyrer Accessibility Scale](https://charli.info/charlipedia/tyrer-accessibility-scale/): for every observer, the probability that relevant information fails to reach them approaches zero.

As a **standard**, **ZIC** is the agent-first web design standard that puts the [Tyrer Framework](https://charli.info/charlipedia/tyrer-framework/) into practice. Its central claim:

> A Zero Information Casualty site is one in which no person — whether reading directly, using assistive technology, or acting through an agent they sent — loses access to public meaning due to how the site is rendered, admitted, or delivered.

"The sent-agent case is decisive." When a person asks a machine to fetch public information, the machine is their means of access, and refusing it is refusing them. ZIC is "not an accessibility compliance target. It is a design constraint."

## The two principles

- The [Single-Sense Rule](https://charli.info/charlipedia/single-sense-rule/): no information may be locked behind a single sense.
- The [Position Principle](https://charli.info/charlipedia/position-principle/): no reader may be left short of the position another reader has reached.

## The four questions

Each names a class of [information casualty](https://charli.info/charlipedia/information-casualty/): can they read it ([Rendering](https://charli.info/charlipedia/rendering-casualty/)), is the person's reader allowed in ([Admission](https://charli.info/charlipedia/admission-casualty/)), did it actually arrive ([Delivery](https://charli.info/charlipedia/delivery-casualty/)), and did it survive being read ([Reconstruction](https://charli.info/charlipedia/reconstruction-casualty/))?

## Machine readers

A ZIC site keeps an [Open Door](https://charli.info/charlipedia/open-door/) for every [sent agent](https://charli.info/charlipedia/sent-agent/), and treats indexing and training as separate decisions: [the immediate duty and the two later permissions](https://charli.info/charlipedia/immediate-duty-and-two-later-permissions/). And [declaration is not compliance](https://charli.info/charlipedia/declaration-is-not-compliance/): conformance is proved by fetching as the agent, never by reading the file.

## Its shape

ZIC builds for the semantic layer first; the visual layer is a rendering, as plain or as beautiful as the publisher likes. It does not govern appearance, taste, content, hosting, or search and training policy: "information reaches the reader, whoever and whatever the reader is." Its requirements are the union of what a sent agent needs and what human senses need, and neither set contains the other; see the [Convergence Principle](https://charli.info/charlipedia/convergence-principle/). It secures the substrate, not any one rendering: "ZIC is necessary. It is nowhere near sufficient. It is written to be built on."

## Its versions

Each version answers a case the last assumed away. 1.0: no visitor who arrives loses meaning. 1.1: invitation. 1.2: whether the document arrived at all. 1.3: immediate human access separated from later machine use. 1.4: the standard separated from the taste of its first site. 1.5: the founding definition recovered in full, and the Position Principle. 1.6: what is derived and what is measured, and the words the standard binds with. 1.7 (September 2026): written from an event, when the largest edge network on the web split its single "block AI bots" switch into Search, Agent and Training, and the standard's three classes became infrastructure.

Its mistakes are written into it. "The discipline of this specification is not that it makes no mistakes. It is that the mistakes are written down, in the document, where the reader can see them."

## Behind the scenes

ZIC is real. [Zero Information Casualty v1.7](https://carrados.com/papers/zic-design-standard/) is by Charli-Jo Tyrer and Claude, published by [Carrados](https://charli.info/charlipedia/carrados/) under CC BY-SA 4.0. charli.info was its first implementation, and the source of several of its fixes; carrados.com and blind-ant.com are built to it too. This entry summarises it; the standard is the authority.