Question related to domain names and less to bind straight.

[SM]

At 22:04 04-09-2012, Eliezer Croitoru wrote:
>I am working on a blacklist and in order to filter the list and to 
>do some Error checks I first want to identify the TLD part of the 
>domain to make the search prefix at least of the domain and not the tld.
>
>the basic list exists at: http://data.iana.org/TLD/tlds-alpha-by-domain.txt
>
>But in a case of a regional tld such as "il" I want to filter the 
>domain in the second 3rd level.
>
>is there an rfc that talks about regional tld?

No.

>is there any known restriction for regional tlds sub-domains naming?

It's ccTLD policy.

See the public suffix list for an informal lower level break-down.

Regards,
-sm