There isn't any way with the current configuration. This would end up being a custom code modification. One thing to consider is that you would leave an open door for spammers. You may eventually find your forum flooded with unwanted messages, and most likely some inappropriate ones. registering at least forces them to go through the captcha, if you have it enabled.

Thanks Darryl. I'd be looking to moderate guest posts to weed out spammers. Legit guest comments will be great for fresh new sites to drive user engagement so this feature would be a plus.

FYI I managed to get the comment box to show for guest users via the role authorisations in the database. They are directed to the login page when submitting the post. That would have to do for now.

Okay. There are some around here that do custom work. You may try reaching out to them. iDragon, Oxwall Accessories, Ebenezer Obasi are a few that I see active on the forums.