As far as I know, per annum is actually a part of the English language. I typically have seen it used in the context of pricing or finance which seems to be ver

As far as I know, per annum is actually a part of the English language. I typically have seen it used in the context of pricing or finance which seems to be verified. [1] I don't disagree with you about p.a. less clear than /yr though. 1. http://english.stackexchange.com/questions/3933/what-is-the-difference-between-per-year-and-per-annum http://english.stackexchange.com/questions/3933/what-is-the-...