# Key number topics

The Canadian legal system organises its case law using a number system for different areas of law. You can browse vLex content using the **Maritime Law Book (MLB) Key Number System**; there are over 100 topics and tens of thousands of sub-topics.

Go to **Browse** and set your jurisdiction to Canada. Among the other options, you will see the **Key number topics** menu. Select it to explore the complete catalogue.

![](/files/-MfDhMWiY9HoATklTwEc)

{% hint style="info" %}
Combine key number topics with alerts and get notified about new case law that falls into any category.
{% endhint %}

{% hint style="danger" %}
Key number topics are only available up to 2017.
{% endhint %}


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# Agent Instructions: Querying This Documentation

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```
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```

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Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.