Oh hohoho! Is it reaaaaalllly? :lol: Apostrophe s is used for three things! Contractions (it is-it's, does not-doesn't), which it hasn't been in this case. Showing possession (Slimey's dog is Piri, Surroundx's grammar is terrible. That is a poor example, i don't think Surroundx needs and s for possession.) Finally for pluralising acronyms and contractions! Seeing as typo is a contraction for typographical, it is accurate to use an apostrophe s ('s) for its pluralisation!