Variables

$content or $items

The content or items the template contains. Certain variable names are reserved for consistency:

attributes
Pluggable attributes (class, id, data attributes, RDF, etc.) for the outermost element.
title
Reserved for the title of the template, which can be used for various things, such as headings, label for form elements, summary for details, legend for fieldset, etc.
$prepend
Similar to jQuery's .prepend(), it prints as the first child in the template.
$append
Similar to jQuery's .append(), it prints as the last child in the template.
$object
Contains the current object, i.e. entity, block, field, etc.
$context
Contains information about the context.