> **PROTOTYPE:** a suggestion, not an official CIAAW or IUPAC page. Official values are at [ciaaw.org](https://ciaaw.org).

# Revision Example

> **The new value on this page is invented.** It only demonstrates what the data looks like after a revision. It is not a CIAAW value, not even a proposed one.

When CIAAW revises a value, nothing is edited or deleted. The converter compares the new table with the previous output and then:

1. creates a new declaration with the new value,
2. moves the element's current pointer to it,
3. flags the old declaration as deprecated and links the two, and
4. keeps every declaration in the element's history.

## hydrogen

```mermaid
flowchart LR
    Hydrogen["element:Hydrogen"]
    AW_H_standard_2027["ciaaw_draft:AW-H-standard-2027<br/>[1.007 85, 1.008 12]<br/>current"]
    Hydrogen -- "ciaaw:hasDeclaration" --> AW_H_standard_2027
    Hydrogen == "ciaaw:currentStandardAtomicWeight" ==> AW_H_standard_2027
    AW_H_standard_2009["ciaaw_draft:AW-H-standard-2009<br/>[1.007 84, 1.008 11]<br/>deprecated"]
    Hydrogen -- "ciaaw:hasDeclaration" --> AW_H_standard_2009
    AW_H_standard_2009 -- "dcterms:isReplacedBy" --> AW_H_standard_2027
```

| Value | Year | Source | Status | Declaration |
| --- | --- | --- | --- | --- |
| [1.007 85, 1.008 12] | 2027 | — | Current | `AW-H-standard-2027` |
| [1.007 84, 1.008 11] | 2009 | — | Deprecated, see `AW-H-standard-2027` | `AW-H-standard-2009` |

The complete file is under [Downloads](downloads.md#revision-example).