The PHP Standard Recommendation (PSR) is a PHP specification published by the PHP Framework Interop Group.The aim is to enable interoperability of components and to provide a common technical basis for an implementation of proven concepts for optimal programming and testing practices. The PHP-FIG is formed by several PHP frameworks founders.
|PSR-0||Basic Coding Standard||It describes the mandatory requirements that must be adhered to for autoloader interoperability||Deprecated and substituted|
|PSR-1||Autoloading Standard||It comprises what should be considered the standard coding elements that are required to ensure a high level of technical interoperability between shared PHP code||Accepted|
|PSR-2||Coding Style Guide||It considers PSR-1 and it is intended to reduce cognitive friction when scanning code from different authors. It does so by enumerating a shared set of rules and expectations about how to format PHP code.||Accepted|
|PSR-3||Logger Interface||It describes a common interface for logging libraries.||Accepted|
|PSR-4||Autoloading Standard||It describes a specification for autoloading classes from file paths. It is fully interoperable, and can be used in addition to any other autoloading specification, including PSR-0. This PSR also describes where to place files that will be auto loaded according to the specification||Accepted|
|PSR-5||PHPDoc Standard||The main purpose of this PSR is to provide a complete and formal definition of the PHPDoc standard. This PSR deviates from its predecessor, the de facto PHPDoc Standard associated with phpDocumentor 1.x, to provide support for newer features in the PHP language and to address some of the shortcomings of its predecessor.||Accepted|
|PSR-6||Caching Interface||The goal of this PSR is to allow developers to create cache-aware libraries that can be integrated into existing frameworks and systems without the need for custom development.||Accepted|
|PSR-7||HTTP Message Interface||It describes common interfaces for representing HTTP messages as described in RFC 7230 and RFC 7231, and URIs for use with HTTP messages as described in RFC 3986.||Accepted|
|PSR-8||Huggable Interface||It establishes a common way for objects to express mutual appreciation and support by hugging. This allows objects to support each other in a constructive fashion, furthering cooperation between different PHP projects.||Draft|
|PSR-9||Security Disclosure||It gives project leads a clearly defined approach to enabling end users to discover security disclosures using a clearly defined structured format for these disclosures.||Draft|
|PSR-10||Security Advisories||It gives researchers, project leads, upstream project leads and end users a defined and structured process for disclosing security vulnerabilities.||Draft|
|PSR-11||Container Interface||It describes a common interface for dependency injection containers. The goal is to standardize how frameworks and libraries make use of a container to obtain objects and parameters (called entries in the rest of this document).||Draft|
|PSR-12||Extended Coding Style Guide||It extends, expands and replaces PSR-2, the coding style guide and requires adherence to PSR-1, the basic coding standard.||Draft|
All the above content is referenced from https://en.wikipedia.org/wiki/PHP_Standard_Recommendation.