 Today, we'll address Maria Quiara's question about canonicalization. You can indicate your preference to Google using these techniques, but Google may choose a different page as canonical than you do for various reasons. So what are these reasons? Let's take a brief step back. It's quite common for a website to have multiple unique URLs that lead to the same content. The really common one is when the dub-dub-dub version of a site shows the same content as the non-dub-dub-dub version of the website. Most websites are set up in this way. Another common configuration is when the homepage is accessible as index.html or when upper and lower case in URLs leads to the same pages. Ideally, we wouldn't even run across any of these alternate versions, which is why we recommend picking one URL format and using it consistently across your website. In practice, life is rarely perfect and we discover all sorts of URLs leading to the same content. For search, it doesn't make much sense to index and show all of these versions, so we try to pick one and focus on that. But how does Google pick the chosen one, the canonical URL? We try to pick the canonical URL by following two general guidelines. First, which URL does it look like the site wants us to use, so what's the site's preference? And secondly, which URL would be more useful for the user? When it comes to the site's preference, we look at a number of things. That includes the link rel canonical annotation, which sites can use, but also redirect, internal linking, which URL is in the sitemap file. We also prefer HTTPS URLs over HTTP URLs and try to pick nicer looking URLs when we can. For all these, we consider the factors involved for each potential canonical URL and then pick the one where more things come together. So if you're a site owner and you have a strong preference regarding URLs that you want to have shown to users in search, first of all, you should make sure that you use those preferences consistently across your website. Ideally, search engines wouldn't even be able to stumble across any of those alternatives. If you have a preference, then stick to it. Along that line, make sure that all of the canonicalization factors that we mentioned are similarly aligned. Make sure that internal links use your preferred URL format. Make sure that sitemap files only list preferred URLs. Make sure that the rel canonical link elements on these pages match. The more you can be consistent, the more likely Google systems will follow your lead and use those two. But what happens when a different URL is chosen? Simply put, it's just the URL that's shown in search. If our systems pick a different URL as a canonical, it'll rank just the same in search. In the end, it really just comes down to your preference. If you have a preference regarding the URLs, then let search engines know unmistakably. But if not, that's fine too. And if a different URL happens to be chosen from time to time, that's not going to negatively affect the site either. Thank you for watching, and I'll see you again in one of the next episodes of Ask Google Webmasters.