The phrase "format style" refers to the way something is organized, presented, or arranged. It describes the specific way in which information, text, or documents are designed to look visually. Full definition
You can choose from a variety of formatting styles, disciplines, and academic levels to compile an order with the topic and requirements. (essaymaxi.com)
For instance, did you know that there are various formatting styles for specific types of writing? (getgoodgrade.com)