# How diagrams are saved

Worth five minutes if you ever need to debug a diagram, migrate one, or explain the storage model to a security reviewer.

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## A save writes in two places

![Data Save Process](https://help.gocapable.com/images/att1423998992.svg)

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## The two records

| **Record**                | **Holds**                                              | **Lives**                                      |
| ------------------------- | ------------------------------------------------------ | ---------------------------------------------- |
| **Custom content**        | The diagram source itself, plus its language.          | In your Confluence site, attached to the page. |
| **The macro on the page** | A pointer to that source, its title, and a hash of it. | In the page body.                              |

The hash is how the page knows whether the picture it is showing still matches the source. If they disagree, the diagram is re-rendered rather than showing something stale.

ℹ️

**This is also why diagrams survive an uninstall.** The source is ordinary Confluence content in your own site, so it is backed up, restored and exported with everything else.

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## A few things that follow from this

* Copying a page copies the source too, so the copy is independent. Editing one does not change the other.
* Deleting a page deletes its diagram source with it, the same as any attachment.
* Page permissions govern the diagram. If you can read the page, you can see the diagram. See [Security and privacy](https://help.gocapable.com/diagrams/security-and-privacy.html).

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## Related

[How diagrams workThe wider render path.](https://help.gocapable.com/diagrams/overview.html)

[Security and privacyWhat leaves your site.](https://help.gocapable.com/diagrams/security-and-privacy.html)

[TroubleshootingWhen the two records disagree.](https://help.gocapable.com/diagrams/troubleshooting.html)

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_Two records, one truth, kept in step by a hash._