WordPress at a glance
function is not described

_publish_post_hook() WP 2.3.0

Hook to schedule pings and enclosures when a post is published.

Uses XMLRPC_REQUEST and WP_IMPORTING constants.

Hooks in function
Return

Nothing (null).

Usage

_publish_post_hook( $post_id );
$post_id(int) (required)
The ID in the database table of the post being published.

Code of publish post hook: wp-includes/post.php VER 5.0.3

<?php
function _publish_post_hook( $post_id ) {
	if ( defined( 'XMLRPC_REQUEST' ) ) {
		/**
		 * Fires when _publish_post_hook() is called during an XML-RPC request.
		 *
		 * @since 2.1.0
		 *
		 * @param int $post_id Post ID.
		 */
		do_action( 'xmlrpc_publish_post', $post_id );
	}

	if ( defined('WP_IMPORTING') )
		return;

	if ( get_option('default_pingback_flag') )
		add_post_meta( $post_id, '_pingme', '1' );
	add_post_meta( $post_id, '_encloseme', '1' );

	if ( ! wp_next_scheduled( 'do_pings' ) ) {
		wp_schedule_single_event( time(), 'do_pings' );
	}
}