[Plugin: Verve Meta Boxes] Upload .swf document in file upload field

Yes it is ??

But first you have to enable it in WordPress in general with the following function:

add_filter('upload_mimes', 'custom_upload_mimes');
function custom_upload_mimes ($existing_mimes=array()) {
	$existing_mimes['swf'] = 'application/x-shockwave-flash';
	return $existing_mimes;
}

Thanks to Chris Meller:
https://chrismeller.com/2007/07/modifying-allowed-upload-types-in-wordpress