The Boolean field will add a switch for a true or false values for the content authors to pick from.
Here is an example of how to retrieve the value from a Boolean field which has the API ID switch.
php (sdk v4 or later):
<?php
$example = $document->data->switch;
if ($example) {
echo "This is printed if value is true.<br />";
}
?>php (sdk v3 or earlier):
We do not support the boolean field for V1