This detailed step-by-step guide will teach you how to install publisher-centered Google Analytics custom variables using Google Tag Manager. Here's how to install the Category, Content Type, Publication Date, and Author customer variables.
Google is telling us that we should use a regional subtag on each URL to help Google’s spider figure out what kind of content is on each page and where it is intended. Google will then consider that the content is intended for that region.
Google is now including the ability to differentiate between regions that basically speak the same language but have slight differences (e.g., Mexican Spanish vs. Spain Spanish). Like the canonical tag, the implementation falls on website owners.