I was trying to decide if et al needed a serial comma – and I came across this:
In Bournemouth, England at least, “plain language” means you can’t use these: E.g., bona fide, and more (etc. too)
Excerpt from the story at Newstin dot com: Town halls ban staff from using Latin words, in case they confuse immigrants:
“Bournemouth Council, which has the motto Pulchritudo et Salubritas – meaning beauty and health – has banned staff from using 19 Latin words Town halls have banned employees from using Latin words on documents because they could confuse people who don’t speak English as their first language. The move has infuriated classical scholars who have blasted it as the ‘linguistic equivalent of ethnic cleansing’….” (read full post)
Re et al and serial commas: it depends on who you ask but most style manuals say in a list of names, you don’t need the comma: e.g. Horatio Alger, Albert Einstein et al. But you’re not entirely wrong if you use one.