In this article from Screencraft, Ken Miyamoto describes the basics of properly formatted scene headings and how they differ from sluglines.

Screenwriting Basics: The Keys to Writing Correct Scene Headings. (2018, December 05). Retrieved July 20, 2019, from https://screencraft.org/2018/07/22/screenwriting-basics-the-keys-to-writing-correct-scene-headings/