Telephone country codes never begin with zero.
Telephone country code +68, dialed as 00 68 from many places, is an incomplete code for an island in the Pacific Ocean. You need one more digit to determine the country.
Telephone country code +8, dialed as 006 8 from many places, is an incomplete code for somewhere in Asia, or for a transnational telephone service. You need at least one or two more digits to determine which one.
To reduce the possibility of confusion, it is best to quote an international telephone number beginning with the single plus symbol and the correct telephone country code (e.g., +685 or +886), omitting any dialing prefix.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
The 00 is not part of the country code; it is an international dialing prefix. There are several country codes +68X, all for various islands in the Pacific, but you need the next digit.
Several South Pacific Islands have 3 digit codes that start 68
'00' is an international dialing prefix, not part of the country code. Country codes beginning with 68 are in the Pacific Ocean, but you need the next digit.
'00' is not part of the country code, it is a commonly used international access prefix. Country code +686 is Kiribati, an island nation in the Pacific.
+689 this is which country code?
Several South Pacific Islands
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
There is no 909 country code.
There is no telephone country code +897, nor +89, nor any other country code beginning with +89. There are no valid telephone numbers beginning with +89.
Gibraltar is country code +350.
Moldova is country code +373.
Slovenia is country code +386.
Togo is country code +228.
Liberia is country code +231.
Angola is country code +244.
Mozambique is country code +258.