Top level Domains

## Some information about top level domains

The rightmost part of the Internet address is called the top level domain which tells to which country or network the address belongs to. If it's a FQDN as defined by RFC920it can be resolved using the hierarchical Domain Name Service for delivery.

FI
  The official country code for Finland. Under it there's organizations of which there's even an up to date list available.
SE, SU, EE, FR...
  two character ISO country codes used by most countries in the Internet. Under it most have organizations but some have first type classifications like AC for Academic Commmunity or CO for Commercial organizations. Larry Landweber's Global connectivity table and map is a regularly updated source of country information.
.edu, .com, .org, .gov, .mil, .net
  Traditional Internet domains used mainly in US and by some international organizations. They refer to the type of organization: EDUcation, COMmercial, ORGanization, GOVernment, MILitary or NETwork.
US
  The official coutry code for United States is also used by some places as a geographical hierarchy. E.g. postmaster@nri.reston.virginia.us points to NRI located at Reston, Virginia, USA.
.UK
  United Kingdom, also a traditional top level domain used in the JANET network in UK before Internet became global. Their official country code is .GB but it's used only on some mail systems there yet. Also they use reverse ordering of domains locally so if you see a strange top level domain in an address where there's UK on the left it's you can try to reverse it. E.g. postmaster@uk.ac.rl.ib is postmaster@ib.rl.ac.uk in the Internet.
.bitnet, .earn
  Unofficial pseudo domains for forwarding mail from here to the EARN/BITNET network. They may not work everywhere. Actually user@node.bitnet is shorthand for @figbox.funet.fi:user@node.bitnet which is an address directing the BITNET address to the gateway called FIGBOX.
.uucp
  Unofficial pseudo domains for forwarding mail from here to the Unix to Unix CoPy network. Most of them have moved under registered Internet domains. Here it forwards mail to gateway uunet.uu.net.
.decnet, .fudec, .hepnet, .span
  Unofficial pseudo domains for forwarding mail from here to the Academic DECNET networks like FUNET's DECNET subnet, High Energy Physics Network and Space Analysis Network (NASA/ESA). Forwards mail to FIGBOX gateway.

See address translation guidefor more information on interpreting strange looking addresses.