Hidden Templates
Sometimes it is undesirable to allow access to a template via a URL. For
instance, a template that you only use as an embedded template would likely be an incomplete HTML document, and you
wouldn’t want visitors to be able to view that template by itself on the
front-end of your site.
“Hidden” templates are just that: templates that cannot be accessed from
a URL, but can be used as embedded templates. To make a template
“hidden”, simply give it a name preceded by an underscore, e.g.
_my_hidden_template.
When a Hidden Template is Requested as a URL
When someone attempts to access a hidden template via a URL, one of
two things will occur. If you have specified a 404 template in your
Template Settings, then the 404
template will be displayed, with 404 headers. If you have not specified
a 404 template, then the index template of the requested template group
will be displayed.
Changing the Hidden Template Indicator
By default, a template is hidden when an underscore prefixes the
template name, but this can be changed with a configuration variable set
in system/user/config/config.php:
$config['hidden_template_indicator'] = '.';