Start by reading this link-https://isrc.ifpi.org/en/ - In the how it works paragraph, roll over the light grey box. Next click the “See the code Syntax for more information” . Read & digest. Now click the “validating ISRC codes”. Read town to “See Country Codes” for a list of countries. Finally have a pint or two. You have just reached the next level of OCD. 
1 Like
Note that, depending on registrant, year is either year of recording or remix (most useful, IMO) or year of registering the ISRC (least interesting, IMO).
2 Likes