In writing, an organization structure or mode refers to the way details in a paragraph or text are organized or the pattern details follow which include chronological organization, the order of importance, cause and effect organization, sequential organization, compare-and-contrast organization, among others. Additionally, most texts include only one organization mode but it is possible a text includes different organization structures. For example, a text dealing with the development of the Second World War can use first a chronological organization to describe the events related to the war and later use cause and effect organization to analyze the triggers and consequence of the war. Therefore, it is true more than one organizational structure or mode may be present in a text.
Often stage directions are in italics or parenthesis, so I would go with that. I have seen capital letters but that's rarer, and I would definitely not say bold.
