Factual error: A very common error in First World War films. British soldiers were not permitted to shave their upper lips until 1916 - in 1914 almost all (unless physically unable to grow them) would have had moustaches.
Factual error: One of Angel's lyrics (in "Today For You, Tomorrow For Me) refers to the movie "Thelma and Louise." Rent (the movie) is set in 1989-90. "Thelma and Louise" was released in 1991. This was caused when they did the move from Broadway to the screen. The stage show did not specify the year. So when they adapted the stage show to the movie, they didn't check the references. Plus it just sounds cool. (00:28:25)
Factual error: On Day 3, look at The Embrey Star newspaper when it zooms into the headline. Above the headline is the newspaper's web address, hardly appropriate given the paper is from 1980.