The Oxford comma. A comma before an ‘and’, but also incredibly divisive.
But there is one place the Oxford comma never belongs – in your meta tags. In my work in SEO I see a bunch of people using them in description tags in particular.
But as a rule of thumb, the more commas in your SEO meta tags the worse off you’re going to be. Search Engines (and Google is pretty up-front about this) see commas in light of the old keyword meta tags – as a way to list keywords in a list.
Description tags are really meant to be in sentence structure. And the more commas you have the more likely your page is to trip search engine’s keyword stuffing alarms. 🚨
However you feel about the Oxford comma, it has no place in your search engine optimisation.