Users will occasionally come to a page that doesn't exist on your site, either by following a broken link or typing in the wrong URL. Having a custom 404 page30 that kindly guides users back to a working page on your site can greatly improve a user's experience. Your 404 page should probably have a link back to your root page and could also provide links to popular or related content on your site. You can use Google Search Console to find the sources of URLs causing "not found" errors31.
However, you may encounter pages with a large amount of spammed forum discussions or spammed user comments. We’ll consider a comment or forum discussion to be “spammed” if someone posts unrelated comments which are not intended to help other users, but rather to advertise a product or create a link to a website. Frequently these comments are posted by a “bot” rather than a real person. Spammed comments are easy to recognize. They may include Ads, download, or other links, or sometimes just short strings of text unrelated to the topic, such as “Good,” “Hello,” “I’m new here,” “How are you today,” etc. Webmasters should find and remove this content because it is a bad user experience.
When referring to the homepage, a trailing slash after the hostname is optional since it leads to the same content ("https://example.com/" is the same as "https://example.com"). For the path and filename, a trailing slash would be seen as a different URL (signaling either a file or a directory), for example, "https://example.com/fish" is not the same as "https://example.com/fish/".
I think the anchor text links in internal navigation is still valuable – but keep it natural. Google needs links to find and help categorise your pages. Don’t underestimate the value of a clever internal link keyword-rich architecture and be sure to understand for instance how many words Google counts in a link, but don’t overdo it. Too many links on a page could be seen as a poor user experience. Avoid lots of hidden links in your template navigation.
Another reason is that if you're using an image as a link, the alt text for that image will be treated similarly to the anchor text of a text link. However, we don't recommend using too many images for links in your site's navigation when text links could serve the same purpose. Lastly, optimizing your image filenames and alt text makes it easier for image search projects like Google Image Search to better understand your images.
QUOTE: “We are a health services comparison website…… so you can imagine that for the majority of those pages the content that will be presented in terms of the clinics that will be listed looking fairly similar right and the same I think holds true if you look at it from the location …… we’re conscious that this causes some kind of content duplication so the question is is this type … to worry about? “
QUOTE: “Cleaning up these kinds of link issue can take considerable time to be reflected by our algorithms (we don’t have a specific time in mind, but the mentioned 6-12 months is probably on the safe side). In general, you won’t see a jump up in rankings afterwards because our algorithms attempt to ignore the links already, but it makes it easier for us to trust the site later on.” John Mueller, Google, 2018