A coding standard in PHP_CodeSniffer is a collection of sniff files. Each sniff file checks one part of the coding standard only. Multiple coding standards can be used within PHP_CodeSniffer so that the one installation can be used across multiple projects. The default coding standard used by PHP_CodeSniffer is the PEAR coding standard.
PHP_CodeSniffer requires PHP version 5.1.2 or greater.
it can also be used to define a set of Coding Standards for your project.