Firefox 3 will ship with a Mozilla maintained list of public domain name suffixes in an attempt to provide better security and UI features to Firefox users. It was announced via the W3C IETF HTTP-WG mailing list by a Mozilla employee:
We are maintaining a list of all “Public Suffixes”. A Public Suffix is a domain label under which internet users can directly register domains. Examples of Public Suffixes are “.net”, “.org.uk” and “.pvt.k12.ca.us”. In other words, the list is an encoding of the “structure” of each top-level domain, so a TLD may contain many Public Suffixes. This information is used by web browsers for several purposes - for example, to make sure they have secure cookie-setting policies.
Via http://publicsuffix.org/learn/
The Public Suffix List is a cross-vendor initiative to provide an accurate list of domain name suffixes.
A lot of feedback is pouring in … most of it seems to be kinda knee-jerk.
One of the better follow-ups is from Paul Hoffman:
One possible method is to start Firefox 3.0 with an empty registry, and fetch a registry update from Mozilla each time a user does either a manual or automatic “check for updates” on Firefox. Checking for updates (as compared to getting updates) happens often enough for users who care about updates to minimize the negative effects of TLD policy changes for those users. By starting with an empty registry, people who never update have the same interface issues they have today with Firefox 1 and 2. This proposal does not involve a per-domain lookup, thus avoiding a lot of overhead and privacy issues.