option_enable_xmlrpc │ filter-hook │ WP 1.0

This filter is documented in wp-includes/option.php

Usage

add_filter( 'option_enable_xmlrpc', 'wp_kama_option_enable_xmlrpc_filter', 10, 2 );

/**
 * Function for `option_enable_xmlrpc` filter-hook.
 * 
 * @param  $true   
 * @param  $string 
 *
 * @return 
 */
function wp_kama_option_enable_xmlrpc_filter( $true, $string ){

	// filter...
	return $true;
}

$true

-

$string

-

Where the hook is called

$is_enabled = apply_filters( 'option_enable_xmlrpc', true, 'enable_xmlrpc' );

Where the hook is used in WordPress