An Availability Zone is represented by a region code followed by a letter identifier;
for example, us-east-1a. To ensure that resources are distributed across the Availability
Zones for a region, we independently map Availability Zones to identifiers for each
account. For example, your Availability Zone us-east-1a might not be the same location
as us-east-1a for another account. There's no way for you to coordinate Availability
Zones between accounts.