.co.at intended for commercial enterprises

.or.at intended for organizations.

[1]

Legal issues[edit]

As a result of ICANN's generic top-level domain (gTLD) expansion,[16] the risk of domain squatting has increased significantly. For example, based on current regulations, the registration of the gTLDs .olympics or .redcross is not allowed; however, the registration of sites such as olympics.example or redcross.example is not controlled.[17] Experts say that further restrictions are needed for second-level domains under the new gTLD .health, as well. For example, second-level domains under .tobacco.health or .diet.health can be easily misused by companies and therefore are a potential threat to Internet users.[18]

Single-letter second-level domains

Domain Name System

Top-level domain

Country code top-level domain

Subdomain

Private sub-domain registry

Public Suffix List

.ac (second-level domain)

.edu (second-level domain)