Clarifications.

README.md

@@ -1,6 +1,12 @@
 SafeCrystals
 ------------
-Prevent Ender Crystals from exploding and breaking blocks or damaging entities.
+A Bukkit plugin to prevent Ender Crystals from exploding and breaking blocks or
+damaging entities.
 
-Players who can build in a region can break the crystals causing them to drop
-as an item.  That event is recorded in the server log.
+Players who can build in a WorldGuard region can break the crystals, causing
+them to drop as an item. That event is recorded in the server log. Projectiles
+launched by the player are handled the same as if the player had attacked the
+Ender Crystal directly.
+
+Players are prevented from placing Ender Crystals in a region if they don't have
+build permission.