That information about html tags is used on pretty much every comment form.
It's helpful to people who want to submit comments so that they know the acceptable html tags that will be allowed. It allows text to be styled in a certain way. For example, if someone wanted to comment on your beer brewing site, they could say:
Really great article. I've been working on some recipes too.
I think that adding raspberry to beer is great!
A person could surround the 2nd line with
<strong> opening and closing tags to make it bold.
Same goes for all the rest of the tags. Notice that even commenting on this site tells the commenter what allowed markup is allowed.
It's no worries. It's normal and is included with comment forms.