Tags are a Subversion concept that allows developers to identify a group of files at a specific point in time and label them with a name. This name can be used to specify the version of your plugin that https://wordpress.org visitors will be able to download. While this recipe specifies a value of trunk as the Stable Tag, indicating that the latest version of the files uploaded to the plugin's trunk folder will be released, it's possible to indicate any other tag name in this field. In addition to keeping your work more organized, working with tags allows you to commit partially implemented new plugin features to your repository without having them automatically available for all to access.