Source

File: wp-includes/post-formats.php

function get_post_format_strings() {
	$strings = array(
		'standard' => _x( 'Standard', 'Post format' ), // Special case. Any value that evals to false will be considered standard.
		'aside'    => _x( 'Aside', 'Post format' ),
		'chat'     => _x( 'Chat', 'Post format' ),
		'gallery'  => _x( 'Gallery', 'Post format' ),
		'link'     => _x( 'Link', 'Post format' ),
		'image'    => _x( 'Image', 'Post format' ),
		'quote'    => _x( 'Quote', 'Post format' ),
		'status'   => _x( 'Status', 'Post format' ),
		'video'    => _x( 'Video', 'Post format' ),
		'audio'    => _x( 'Audio', 'Post format' ),
	);
	return $strings;
}