I’ve never read anything about it being mandatory and I’ve never seen it specified in a course, but it could be helpful for anyone doing SEO.
Don’t think that’s even a thing, there is no such link type
I found that attribute in the technical documentation example project on CodePen. It confused me too.
that is only used when you’re assigning a stylesheet to your html or other external file where you tell the browser what is the file’s relationship to html
The projects need to be updated, they have a bunch of invalid HTML. I have updated some of the projects in the repo but the Codepen’s are still not updated. Not sure when they will be.
Anyway, it is invalid HTML.
Error: Bad value internal for attribute rel on element a: The string internal is not a registered keyword.