25

I realize that this question might not make sense to some, but I was just curious of why the domain names built starting from most specific and ending with most global identifier.

www.google.com

[most specific].[2nd level].[top level]

All other tree traversing formats, syntax conventions and identifiers (at least ones that I'm aware of) start with the most global namespace and end with the most specific node.

  • Filepath: /root/subfolder1/subfolder2/file
  • Component: com.android.notepad.NoteEditor
  • Object: rootObject.subObject1.subObject2
  • IP: 1.2.3.4
  • Newsgroups: comp.lang.java.help
  • Phone numbers: +1-555-555-1234

So I guess my question is whether there is any productive reason behind this special treatment of domain names by specifying them backwards, or it was just decided by throwing a coin?

EDIT:

More examples of forward conventions:

  • Address (Russia): Country, City, Street House/Apt
  • Date (Japanese and DB): YYYY-MM-DD
  • Time: HH:mm:ss

Examples of Backward conventions:

  • Address (US): Street House/Apt, City, State, Country
  • Date (European): DD/MM/YYYY

The most specific first makes sense when addressing is identifiable easier and happens more often on local scale.

Mixed order:

  • Date (US): MM/DD/YYYY - While Month gives more meaning to the Day, the Year is moved to be the last, because it less needed to uniquely identify the date in day-to-day use.
Unirgy
  • 1,495
  • 15
  • 25
  • I've used minis where the filesystem was . (just two levels) – 6502 Jan 12 '11 at 00:10
  • +1 I want to know too! Great broad examples btw. – Yuji 'Tomita' Tomita Jan 12 '11 at 00:14
  • When you send a letter, the country comes last as well. – Debilski Jan 12 '11 at 00:27
  • 1
    @Debilski - While this is true for US, it is not a global convention. In Russia, for example, it's Country first, then City, then Street, and then House/Apt. Although it is a smart system to write least specific in address, because historically, most of communication happened on local level, and less frequently on more global, so it was a solution for redundancy. It makes much less sense in domain names. – Unirgy Jan 12 '11 at 00:33
  • 1
    So that when you play them backwards you hear beatles songs. – bmargulies Jan 12 '11 at 00:39
  • @Unirgy: Interesting. Did not know that about the Russian convention. – Debilski Jan 12 '11 at 10:18

2 Answers2

9

Take a look at the book "Where the Wizards Stay Up Late" for details on how host names came to be. It's really more like a coin flip. Paul Vixie, the godfather of DNS and BIND is still alive (and I think in SoCal), he could probably answer it better than I.

I often thought of writing a browser addon that allows left to right hierarchical URLs in place of the current right to left.

P

Paul Vilevac
  • 641
  • 6
  • 2
3

Reading through these:

It seems like it was just following the convention.

Noon Silk
  • 54,084
  • 6
  • 88
  • 105