constant REQUIREMENT_OK

backdrop_requirements_severity in core/includes/install.inc

Extracts the highest severity from the requirements array.

file_requirements in core/modules/file/file.install

Implements hook_requirements().

image_requirements in core/modules/image/image.install

Implements hook_requirements() to check the PHP GD Library.

node_requirements in core/modules/node/node.module

Implements hook_requirements().

system_requirements in core/modules/system/system.install

Implements hook_requirements().

... See full list