Bukkit

This is what the permissions section of the plugin.yml file looks like.

permissions:
    circle.*:
        description: Gives access to all circles
        children:
            circle.teleportation: true
            circle.micro: true
            circle.transmutation: true
            circle.set.*: true
    circle.teleportation:
        description: Allows you to use teleportation circles
        default: true
    circle.micro:
        description: Allows you to use micro circles
        default: true
    circle.transmutation:
        description: Allows you to use transmutation circles
        default: true
    circle.set.*:
        description: Allows you to use all set circles
        default: true
        children:
            circle.set.1234: true

For the circle.set children, 1234 isn't the only one. Each type of set circle has it's own permission, with the number of the set circle as the child of circle.set