> ## Documentation Index > Fetch the complete documentation index at: https://clickflare.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Built-in variables > Unlocking ClickFlare Tag Manager's Power: Explore the Built-In Variables for Enhanced Tracking Efficiency Built-in variables are a special category of variables that are predefined and cannot be customized. When you create a new container, it initially contains no user-defined variables, but some built-in variables are already enabled. These enabled built-in variables are accessible across ClickFlare Tag Manager whenever variable selection menus are present. You can access the list of built-in variables, directly from the tags or triggers' section of the container. To check built-in variable from tag configuration: 1. Click on **+ New Tag** 2. Select a tag configuration, like *Custom Event* for example 3. Next to the variable placeholder, click on the "**+"** symbol 4. Go through the list of built-in variables Go through the list of built-in variables You can do the same from the trigger's configuration. Related Sources: * [Built-in variables](/docs/en/tag-manager-1/about-built-in-variables) * [User-defined variables](/docs/en/tag-manager-1/user-defined-variables) * [User-defined variables types](/docs/en/tag-manager-1/custom-variable-types) * [About variables](/docs/en/tag-manager-1/about-variables)