Should I install nofollow plugin for MyBB?

[anush]

Many forums allows its users to add links in their posts. If your forum allow links too then I would recommend to add this plugin. But if you don't then its only the signatures links that will matter, right?? You can make your signature links no-follow through group permissions on mybb.

And coming to google if you make all of your links no-follow strictly via any plugin then won't get any manual action penalties that's for sure. But as Google already ignores low quality links so it will be highly unlikely situation as links from forums are by default considered as very weak links.