If you do not wish to display the notice on all the products, you can set up notice on per-product basis. Head to the Edit Product screen for any product and look for the Product Notice/Information meta box and add the desired content in the Notice Text field. Choose from a set of default appearance…

Global Notice shows up on all the products on your store. In order to set up a global notice, navigate to the Settings menu under WooCommerce on the WordPress Dashboard. Click on the Product Notice tab and use the settings field to set up the product notice that you intend to show on all the…