NGC’s VarietyPlus service has been attributing important U.S. coin varieties for over 20 years now The service has now expanded to include world coins as well. Over 10,000 varieties are covered which are currently listed on www.NGCcoin.com/VarietyPlus. NGC also attributes certain coins automatically without any charge. A fee of $15 is changed for other such requests. Through the online portal you can identify which category a particular variety falls into.
The attribution will be printed on the certification label if the variety is recognized by NGC. High res images of coins which are not recognized can be emailed to service@NGCcoin.com to find out if they might be eligible in the future. NGC plans to update many more world coins to their list over time.
Image Courtesy: NGC