.. include:: /Includes.rst.txt .. _prerequisites: Prerequisites ^^^^^^^^^^^^^ It is assumed that you have a running TYPO3 CMS system (if not, please refer to the :doc:`Installation Guide `) and that you have been through the :doc:`Getting Started Tutorial ` in order to have a general idea of how the TYPO3 CMS backend operates. You may also want to have been through the :doc:`Editors Tutorial ` in order to be familiar with the concepts of pages and content elements. A few more elements that you need to know before starting: - all content elements are stored in a database table called `tt_content` - each content element has a database field called `CType` in which the type of the content element is stored - the `tt_content` table also has a field called `pid` which refers to the page the content element is on - in general, each TYPO3 CMS table has a field called `uid` which contains the primary key (unique id for each record) - you will probably find useful to have a database access to check how information is stored as we proceed along this tutorial