I talked with @Aaron_Kennedy about how my redirect jmp.com/mastering works. He told me that we can request that they create a global redirect (specifically a global redirect, not just any only redirect) that will:
1. ID the geo location of the person (somehow the server knows this ).
2. Direct person typing the global redirect to the correct page on their country's jmp.com site IF there is a page with the identical url that includes only a different country path (like de_de).
So, @Elias_Pickrahn , because I want jmp.com/mastering GLOBAL REDIRECT to go to https://www.jmp.com/en_us/events/mastering/overview.html
and because we have that structure in other countries, if I am in GERMANY, it will go to:
https://www.jmp.com/de_de/events/mastering/overview.html
Und alles ist gut!