hostname.co.uk but hostname.ca; hostname.co.nz but hostname.fr. Why?

Factual Questions
1

This occurred to me while asking about Google’s local sites here.

Why do some countries have a “.co” before their country domain, while some stick the county domain straight on the end of the address?

For instance, Google UK is www.google.co.uk, but Google Canada is www.google.ca. Google New Zealand is www.google.co.nz, but Google France is www.google.fr.

Others with “.co” are South Africa (.co.za), India (.co.in) and Japan (.co.jp)

Most European countries use just the country code: Italy (.it), Germany (.de), Norway (.no), Spain (.es) etc.

Australia and Pakistan, just to be different, have “.com.au” and “.com.pk” respectively. There may be others.

Is there any rhyme or reason to this?

2

Each geographic domain has a different body administering it. In the UK’s case, Nominet. These bodies choose what structure to impose within their top-level domain. It’s all done by mutual agreement, not by any legislation or enforcement.

3

The UK can also have .com.uk:
http://www.google.co.uk/search?as_q=*&num=10&hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&btnG=Google+Search&as_epq=&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_occt=any&as_dt=i&as_sitesearch=.com.uk&safe=images

I was also pretty sure I’d seen some with just plain .uk, too, but it appears I was mistaken. As to the reason, I have no idea.

4

http://www.bl.uk/ (the British Library) is the only exception I’ve seen, and I suspect such oddities predate the agreements that led to the .org.uk-type structure.

5

Nice trick, +MDI. Some more Googling on those lines has revealed that as well as the .co.uk, .ac.uk, .org.uk and .gov.uk, we have .ltd.uk and .plc.uk (limited companies), .mod.uk (Ministry of Defence - military stuff), .sch.uk (schools), .nhs.uk (hospitals) and .police.uk (take a wild guess) and loads more. Who knew? There are some .me.uk things as well, which I guess is some private domain reseller.

6

Interestingly, www.nhs.uk and www.mod.uk work as actual addresses, plus www.gov.uk redirects to another government address. And bizarrely, www.org.uk leads to a regional Mac user group.