$contact
, $assignee
or $system
$contact.name
$contact.firstname
$contact.lastname
$contact.email
$contact.country
$contact.id
$contact.field_name
$contact.city
will be replaced by New York
.$system.current_datetime
$system.current_date
$system.current_time
$assignee.id
$assignee.name
$assignee.email
$assignee.firstname
$assignee.lastname
$assignee.team