autoship_plugin_custom_extensions

(src > admin.php) Allows plugin authors should add their plugin to the extension list. Takes the 1. plugin file name ( with or without the php extension i.e. 'autoship' ) as an argument and adds it to the extensions array. 

Example

function xx_add_plugin_extension ($extension){
    return 'my_extension';
}
add_filter('autoship_plugin_custom_extensions', 'xx_add_plugin_extension', 10, 1);