WordPress at a glance
filter is not described

media_send_to_editor filter-hook . WP 2.5.0

Filters the HTML markup for a media item sent to the editor.

Usage

add_filter( 'media_send_to_editor', 'filter_function_name_4182', 10, 3 );
function filter_function_name_4182( $html, $send_id, $attachment ){
	// filter...

	return $html;
}
$html(string)
HTML markup for a media item sent to the editor.
$send_id(int)
The first key from the $_POST['send'] data.
$attachment(array)
Array of attachment metadata.

Where the hook is called

media_upload_form_handler()
media_send_to_editor
wp_ajax_send_attachment_to_editor()
media_send_to_editor
wp-admin/includes/media.php 740
$html = apply_filters( 'media_send_to_editor', $html, $send_id, $attachment );
wp-admin/includes/ajax-actions.php 2708
$html = apply_filters( 'media_send_to_editor', $html, $id, $attachment );

Where the hook is used (in WP core)

wp-includes/default-filters.php 528
add_filter( 'media_send_to_editor', 'image_media_send_to_editor', 10, 3 );
wp-admin/includes/ajax-actions.php 2681
remove_filter( 'media_send_to_editor', 'image_media_send_to_editor' );