> For the complete documentation index, see [llms.txt](https://docs.themeupstudio.com/crimson/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.themeupstudio.com/crimson/multilingual/content-rules-slugs-must-match.md).

# Content Rules: Slugs Must Match

This is the #1 rule that causes confusion (and 404s) for beginners.

#### The rule

Crimson requires you to use the **exact same slug (URL identifier)** for:

* posts
* pages
* authors
* tags

…across all languages. If you change the slug in one language, Crimson won’t find the “matching” page in the other language and it will result in a 404.

{% hint style="info" %}
This may feel strange at first (because Spanish URLs often look better translated), but it makes language switching reliable with Crimson’s approach.
{% endhint %}

#### Example

If the English post URL is:

* `/blog/getting-started`

Then the Spanish version must also use:

* `/blog/getting-started`

If you instead use:

* `/blog/comenzando`

Crimson won’t recognize it as the same page and it can lead to a 404 when switching languages.

#### Practical workflow for writers/editors

When publishing multilingual content:

1. Decide the “canonical slug” first (usually English-based)
2. Use the same slug in every language version
3. Translate the **title and content**, not the slug