Documents related to 'top-level'
1992, RFC1386: The US Domain
1993, RFC1480: The US Domain
1994, RFC1591: Domain Name System Structure and Delegation
1998, RFC2450: Proposed TLA and NLA Assignment Rule
2000, RFC2921: 6BONE pTLA and pNLA Formats (pTLA)
2001, RFC3071: Reflections on the DNS, RFC 1591, and Categories of Domains