I was trying to explain what a canonical tag was the other day, and I realized (not for the first time), that the canonical tag is not actually a tag. If you break down HTML syntax, it looks something like this:
If you apply that to the syntax of a “canonical tag”, which is usually of the form:
<link rel="canonical" href="https://www.keshkesh.com/" />
Then we see that the canonical is not a tag at all, but is actually the value of the rel attribute within the link tag. Similarly, SEOs often refer to the importance of using “alt tags” for images, when in fact what they mean to say is that you should use descriptive values for the alt attribute within image tags.
So the next time someone mentions adding a “canonical tag” to a site, correct them by pointing out that what they mean to say is that a link tag should be added to the header of the site, with a rel attribute whose value is “canonical”, that also contains an href attribute whose value is the canonical url for that page. It may just make you look smarter, or more likely, pedantic.