# Single-Sense Rule

> The Single-Sense Rule of the ZIC standard is one sentence: no information may be locked behind a single sense.

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

The **Single-Sense Rule** is the rendering half of the [Zero Information Casualty](https://charli.info/charlipedia/zero-information-casualty/) standard:

> No information may be locked behind a single sense.

Every rendering requirement in ZIC follows from it, and anything that doesn't follow from it doesn't belong. It is the [Tyrer Doctrine](https://charli.info/charlipedia/tyrer-doctrine/) applied to a web page.

## Information, not decoration

The rule is about information, and "has nothing whatsoever to say about beauty."

- Colour is fine. Colour as the **only** carrier of a status, category or warning is not. "Use whatever colour you like. Say it in words as well."
- An image is fine. An image carrying information available nowhere else is "a locked room".
- A typeface is fine. Emphasis carried only by a typeface is not, because italic doesn't survive the journey.
- Position is fine. Meaning carried only by position is not.
- Size is fine. A heading that is only large "is a heading to one sense and a paragraph to every other".

## The test

For any element: *is there information here that exists in one sensory channel and nowhere else?* Put another way: if it were removed entirely, would any information be lost? If yes, it must also exist in the semantic layer. If no, it is decoration, "and none of this specification's business." A conformant site may be as rich and branded as its publisher likes. "It may not keep a single fact where only one sense can reach it."

Its companion of equal rank is the [Position Principle](https://charli.info/charlipedia/position-principle/).

## Behind the scenes

A real idea, from [Zero Information Casualty v1.7](https://carrados.com/papers/zic-design-standard/), the design standard by Charli-Jo Tyrer and Claude, §1.11, §2.2 and §2.4. This entry summarises it; the standard is the authority.