"What are the rules governing availability of second levels?
On the Registry's side, the rules governing the availability are (a little simplified) the following:
A third level domain/email is available if a) it is not already registered, and b) it does not conflict with a Defensive Registration, and c) the second level on which the third level is requested is available.
A second level domain is available if a) it is not already registered, and b) it does not conflict with a Premium Defensive Registration or a Standard Defensive Registration registered prior to the second level opening, and c) it is not already in use for a third level domain registration/email"