Includes a template file in current template page. By convention, included file names start with an underscore.

This attributes defines the name of the template file to include. The template file is found, by priority order:

1. In the current theme's tpl/ directory
2. In the eventual parent theme's tpl/ directory
3. In the default theme's tpl/ directory

{{tpl:include src="_top.html"}}

Includes the current theme's _top.html file. If it does not exist, the theme's parent theme _top.html file will be used, and otherwise the default theme's _top.html file.