php.ini directives
PHP Manual

List of php.ini sections

This list includes the php.ini sections you can set to configure your PHP setup on a per Host or Path basis. These sections are optional.

These sections don't directly affect PHP. They are used to group other php.ini directives together and to get them to act upon a particular host or on a particular path.

Sections
Name Changeable Changelog
[HOST=] PHP_INI_SYSTEM Added in PHP 5.3.0.
[PATH=] PHP_INI_SYSTEM Added in PHP 5.3.0.

Here's a short explanation of the configuration directives.

[HOST=<host>]

This section allows you to define a set of php.ini directives that will take effect on the named host.

Example #1 Activate full on-screen error reporting for dev. domain

[HOST=dev.site.com]
error_reporting = E_ALL
display_errors = On

[PATH=<path>]

This section allows you to define a set of php.ini directives that will take effect when a script runs from the named path.

Example #2 Add security script for protected areas

[PATH=/home/site/public/secure]
auto_prepend_file=security.php


php.ini directives
PHP Manual