WordPress at a glance
filter is not described

oembed_linktypes filter-hook . WP 2.9.0

Filters the link types that contain oEmbed provider URLs.

Usage

add_filter( 'oembed_linktypes', 'filter_function_name_8899' );
function filter_function_name_8899( $format ){
	// filter...

	return $format;
}
$format(array)
Array of oEmbed link types. Accepts 'application/json+oembed', 'text/xml+oembed', and 'application/xml+oembed' (incorrect, used by at least Vimeo).

Where the hook is called

WP_oEmbed::discover()
oembed_linktypes
wp-includes/class-oembed.php 454-458
$linktypes = apply_filters( 'oembed_linktypes', array(
	'application/json+oembed' => 'json',
	'text/xml+oembed' => 'xml',
	'application/xml+oembed' => 'xml',
) );

Where the hook is used (in WP core)

Does not used.