Though Phil and Eric had intended to cover all the diacritical marks in the IPA in this podcast, they just couldn’t do it. In fact, Eric’s recorder stopped recording after 45 minutes, though they kept talking for 15 more minutes... so this is merely an introduction to diacritics, not an exhaustive review of all of them. For reference, the boys work their way through the symbols following the order that the wikipedia article on the International Phonetic Alphabet’s section on diacritics takes, so you might want to follow along.