If you have non-HTML pages on your internet site, such as PDFs or spreadsheets, you won’t have the capacity to employ hreflang within the of your HTML because it doesn’t exist.  En muchas ocasiones, en las tiendas on the net se generan URLs que expresan filtros y códigos de seguimiento, https://www.presta-addons-modules.com/en/opencart-seo-automatic-google-rich-snippets-json-ld-integration-opengraph-twitter-tags-schemaorg.html