Before the advent of mobile phones, there were several etiquettes in place for going to a movie as well! If you would go to a theater back in 1912, you would have a few friendly reminders in place regarding movie etiquettes, like removing of hats or to remind you of your umbrella.
These were typically observed in movie theaters back in 1912. Nowadays, most of the notices you see are regarding the non-usage of cell phones or to turn them to silent mode before the movie starts. You can have a look at the posters back then that were struck up on your way to the movie theater.
We could gain access to these images as they had been preserved safely in the Library of Congress and you would be surprised looking at how polite the notices were back then. However, some of the etiquettes can still be applied to our generation, like not getting up from your seat while the screen is on or refraining from talking. Scroll down and have a look at these rare images.