Telephone country codes never begin with zero.
Country code +688, dialed as 00 688 from many places, is Tuvalu.
Country code +88, dialed as 006 88 from many places, is an incomplete code for a country in Asia or for a transnational telephone service. You need one more digit to identify the country or service. For example, +880 is Bangladesh and +886 is Taiwan (Republic of China).
To avoid confusion, it is best to write an international telephone number in correct international format, beginning with the plus symbol and the correct telephone country code (e.g., +688 or +880), omitting any dialing prefix.
(The plus signmeans "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.)
Related Q&A：
Where is telephone country code 00614？-Oh, well, the telephone country code 00614 is for Australia. Yep, Australia is where this code is used. You know, Australia is a great country with amazing landscapes and friendly people. It's quite a popular destination for tourists and has a lot to offer. So, if you see a number starting with 00614, it's likely coming from Australia. Cool, huh?
