Now you can add players to your cuboid by using /ps allow NICK, if you use /ps allow * everyone will have permission but if after that I do /ps remove NICK, that player still has permission.

I have a trap and I want to prevent my clan to use it (disable use stone). Now I can't blacklist my friends so everyone including my clan can trigger the trap. If you add a blacklist instead of a whitelist, I can allow everyone (*) to trigger the trap and blacklist my clan and friendly clans se we are safe when moving aroung my house.

Sorry for my bad english, if someone understands me and can explain it better, please do it :P

Use this flag to reverse the whitelist into a blacklist:

http://wiki.sacredlabyrinth.net/index.php/Field_Flag_Reference#apply-to-reverse