From working with podcast-index.org database to find podcasts, I have learned that for language codes:
ES = Spanish
ES_MX = Mexican Spanish
ES_ES = Double Spanish
(Apparently people don't realize that ES_ES is supposed to be "European Spanish", so when you filter by ES_ES you get podcasts from like wherever)
@pganssle I mean, if Spanish is good, isn't double Spanish twice as good? That's just science.