If I mark a board as accessible to registered members, guests will not see it. I think it's not a good idea, the purpose of registered boards is often to incite guests to register... How do they do it if they cannot see the board they could register for? ;)
Allowing guests to see all Boards but not entering (http://www.simplemachines.org/community/index.php?topic=16281.0)
This (http://custom.simplemachines.org/mods/index.php?mod=610) mod might be easier.
Forgot about that mod. Thanks for reminding me :)
It happens a lot. The tip's page is there since along time and became the de-facto place to look for that thing.
He would have seen the mod, but only somewhere around the last pages.
However when I made that mod for a friend of mine, completely independent from that trick, I posted it in that thread too. It's a bit more flexible, and it's easier to work with then editing source files.
It tried both solutions, with the default theme, none worked... The board accessible to registered members only is still invisible to guests.
Sorry guys..; forget about my previous message, I just saw there are two check boxes columns for a board permissions... checking the visibility one helped...