Recently while discussing about canonicalization at WMW a member (bcrbcr) pointed out an issue with Google Toolbar conflicting with ICANN definition for domain names.
In the languages that utilize Latin characters (e.g., English, Finnish, German, Italian, etc.), each letter has two variants: upper case and lower case. The Internet’s basic DNS and hostname specifications provide that the upper-case and lower-case variants of each letter are considered to be equivalent. Thus, all the variant domain names in the above list are treated as the same domain name.
Now does it apply for example.COM (COM is in upper case) too?
In my opinion yes, “as example is to .com, com is to dot (the fully qualified domain name is example.com. not example.com, the silent dot says a lot about Web architecture“. So the case of the TLD (Top Level Domain) should not matter.
Issue with Google toolbar
Google Page Rank for google.com
- google.com – PR 10 (all lower case)
- GOOGLE.com – PR 10 (The TLD is lower case, rest part is upper case. Even a mix of upper and lower case gives the same PR)
- google.COM – No PR (When the TLD is in uppercase it doesn’t work)
Can this be a problem?
Yes, only from Google’s ranking. Google gives a lot of value to links and PR is just a small indication of its link juice. If Google is considering both these Domains different at PR level then there is a chance that it happens while counting the Link value as well. If some links are coming to example.COM then may be those links won’t be counted under lower case TLD domain (which is technically the same domain). I will need to some experiments to confirm it.
This problem is not there for .co.uk or .co.in. This problem exists for .org. Other TLDs I will have to check.
Linking to http://www.mattcutts.COM as a test case.