I am making a somewhat simple server that consist of a capture-the-flag/pvp with two castles. The, 'flag', is a block of the teams' color, red or blue. On the outside of the fortress has some blue or red blocks. I have heard of a Bukkit plugin that disables certain blocks from being mined, but I need the, 'flag', to be mine able, but not the rest of the blocks. Is there a plugin, or will I have to change it to redstone blocks or lapis?