I would rather use a *Set* here since it has all the properties of it:
* used to test membership,
* elements supposed to be unique,
* no importance of order, ...

```
'read' => array( 'Class' => true, 'Section' => true, 'Owner' => true, 'Group' => true, 'Node' => true, 'Subtree' => true, 'State' => true ),
```

It makes all operations of adding/removing *O*(1) / *Θ*(1).