Anyone have some insights on what a registrar usually needs to do to add a country's TLD? Sounds like it might be the kind of problem that's simple on paper but in practice requires jumping through all kinds of regulatory hoops for each new country. It does seem to be pretty common for registrars to be missing ccTLDs - .ai (for Anguilla), for example, is not supported by some registrars even though it's popular and a…
ccTLDs are the Wild West. It's hard to generalize -- practically every ccTLD does something weird that makes it difficult to support, though.
A few examples of areas where ccTLDs behave significantly differently from gTLDs are:
• Many ccTLDs require registrants to have some form of personal or business presence in the country. The requirements for how the registrant must prove that presence can vary.
• Some ccTLDs have unusual processes surrounding domain expirations and renewals. For example, under some ccTLDs, domains always expire at the end of a month, rather than exactly a year after registration. Additionally, some ccTLDs restrict when domains can be renewed -- for example, .au domains can only be renewed within 90 days of their expiration, and .eu domains cannot be renewed within 5 days of expiration.
• Domain transfers can get weird as well. gTLDs have a standardized process for domain transfer authorization; ccTLDs often modify this system or replace it entirely.