It’s exclusively about the leading vowel sound, rather than an actual vowel. E.g. it is a one-dollar bill, a unicorn, a European country, and an heirloom. There are plenty of initialisms that start with vowel sounds that are even less questionable, e.g. an NFL contract, or an FBI agent, vs a CEO, or a TMI situation. Regional differences exist, but are mostly about whether the leading sound is or is not pronounced, e.g. a historic occasion (american english) vs an historic occasion (british english).












Do people not know their own language when they write shit for publication? It’s proscribed, not prescribed. Fuck.