For some kind of communities this can help greate in SEO.
With this meta tag Big duplicate content can be removed from domain.
How it can be achieved ?
When markdown is enabled those descriptions are parsed as markdown and placed in a <p> tag so they get different styling. You can just reduce the font size from custom CSS tab in acp.
Its possible to assign a group the moderating power on just one category, However be aware that this will also include other moderation powers such as Forking, Closing and Moving topics.