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Contains filters are case sensitve
Namesort descending Description
Database abstraction layer Allow the use of different database servers using the same code base.
File interface Common file handling functions.
Form generation Functions to enable output of HTML forms and form elements.
Formatting Functions to format numbers, strings, dates, etc.
Hooks Allow modules to interact with the Drupal core.
Input validation Functions to validate user input.
Menu system Define the navigation menus, and route page requests to code based on URLs.
Node access rights The node access system determines who can do what to which nodes.
Search interface The Drupal search interface manages a global search mechanism.
Themeable functions Functions that display HTML, and which can be customized by themes.

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