这个documentation 在法典中似乎过时了。

使用以下代码（请参阅注释）：

// Priority 5 allows the removal of default tabs and insertion of other plugin\'s tabs 
add_filter( \'contextual_help\', \'wpse_77308_products_help\', 5, 3 );

function wpse_77308_products_help( $old_help, $screen_id, $screen )
{
    // Not our screen, exit earlier
    // Adjust for your correct screen_id, see plugin recommendation bellow
    if( \'edit-magazine\' != $screen_id )
        return;

    // Remove default tabs
    $screen->remove_help_tabs();

    // Add one help tab
    // For new ones: duplicate this, change id\'s and create custom callbacks
    $screen->add_help_tab( array(
        \'id\'      => \'products-help\',
        \'title\'   => \'Products\',
        \'content\' => \'\', // left empty on purpose, we use the callback bellow
        \'callback\' => \'wpse_77308_print_help\'
    ));

    // This sets the sidebar, which is common for all tabs of this screen
    get_current_screen()->set_help_sidebar(
        \'<p><strong>\' . __(\'For more information:\') . \'</strong></p>\' .
        \'<p>\' . __(\'<a href="http://wordpress.stackexchange.com/" title="WordPress StackExchange" target="_blank">WordPress Answers</a>\') . \'</p>\' .
        \'<p>\' . __(\'<a href="http://wordpress.org/support/" target="_blank">Support Forums</a>\') . \'</p>\'
    );

    return $old_help;
}


function wpse_77308_print_help()
{
    echo \'
        <p>Products show the details of the items that we sell on the website. 
        You can see a list of them on this page in reverse chronological order 
        - the latest one we added is first.</p> 

        <p>You can view/edit the details of each product
        by clicking on its name, or you can perform bulk actions 
        using the dropdown menu and selecting multiple items.</p>
    \';
}

Result:

获取正确的$screen_id, 使用插件Current Admin Info, 出生于两位伟大的Stack贡献者（kaiser和Stephen Harris）。

显示有关当前管理屏幕及其全局、上下文挂钩等的信息。

该信息显示在管理屏幕右上角»上下文帮助«-面板的新选项卡中。