There are a number of Recite CMS-specific plug-ins which are not documented in the Smarty Template Engine manual. Each of these are covered in their respective chapters, and also listed below.
{captcha}. Output a CAPTCHA image. Refer to Adding CAPTCHA to Forms.
{container}. Output a container. Refer to Defining Container Locations
{contentblock}. Output page content. Refer to Defining Editable Areas
{thumbnail}. Create a thumbnail image. Refer to Thumbnails