I need to modified one of my new board. But on this board, I want to allow, everyboard including guest to edit the board. just like people can modified wikipedia.. same idea as wikipedia . i want to use the board like wikipedia
This could be risky as once you edit the post, it can't be "un-edited" if you get my drift.. no backups of the orginal post.
Having said that.
You can set the board to local permissions, then give permissions to guests to edit/post messages.
This link should help you better understand permissions:
http://docs.simplemachines.org/index.php?board=60.0;sort=subject