constant REQUIREMENT_INFO

file_requirements in modules/file/file.install

Implements hook_requirements().

hook_requirements in modules/system/system.api.php

Check installation requirements and do status reporting.

_system_check_db_utf8mb4_requirements in modules/system/system.install

Checks whether the requirements for multi-byte UTF-8 support are met.

system_requirements in modules/system/system.install

Implements hook_requirements().

telemetry_requirements in modules/telemetry/telemetry.install

Implements hook_requirements().

... See full list