The following three models (Model D, E, and F)  explains how an entire US Mint® series can be discovered!The legend for the below models:Black Circle - Current Documented Knowledge DomainBlue Triangle - Addition of new knowledge to the Current Documented Knowledge DomainBlue Text - Addition of new knowledge based on the relatively unstudied/undocumented function of the Bureau of the Mint (1984 name change to US Mint®) to produce special medals for US Government agencies (My assigned term of this US Mint® product is special Government medal).Blue Circle - Creation of a new Documented Knowledge DomainWhy are the majority of special Government medal issues kept secret by the US Mint® ? special Government medals are a joint inter-agency effort between an acquiring US Government agency and the US Mint®. The US Mint® enforces confidentiality of this joint inter-agency effort and does not  released comprehensive production information related to these medals.  A good case example is the President of the United States special Government medal (POTUS sGm) series:http://www.potus-sgm.com/In the case of the POTUS sGm series, from 1958 to the present, the US Mint® has never released comprehensive production and general numismatic information related these special Government medals. It took a numismatic researcher to uncover this US Mint series. One injustice from the withholding this information was the fact that these numismatic medals are true to life presidential artifacts that is unknown by historians, numismatists, and collectors.Model D - Previously Undocumented Issue - The initial discovery of a POTUS sGm and its supporting documentation as an official US Mint issue.Model E - Previously Undocumented US Mint Series - The initial discovery of the 15 types of POTUS sGm and its supporting documentation as an official US Mint issue.Model F -  Previously Undocumented Knowledge Domain - Filling the knowledge void for the newly documented  POTUS sGm Series Knowledge Domain.   This is how a US Mint series was  discovered!