There is no formal ICANN TLD list. The PSL is your best shot. So it is actually wrong to assume that your situation is the sole purpose. For instance, https://

There is no formal ICANN TLD list. The PSL is your best shot. So it is actually wrong to assume that your situation is the sole purpose. For instance, https://data.iana.org/TLD/tlds-alpha-by-domain.txt https://data.iana.org/TLD/tlds-alpha-by-domain.txt Where is .co.uk ? That is - for all intents and purposes - considered a TLD. So PSL is currently doing double-duty and the distinction is very important.