When you apply a paragraph style, character styles and other previous formatting remain intact. After you apply a style, you can override any of its settings by applying formatting that’s not part of the style. When formatting that is not part of a style is applied to text with that style applied, it is called an override. When you select text with an override, a plus sign (+) appears next to the style name. In character styles, an override is displayed only if the applied attribute is part of the style. For example, if a character style only changes text color, applying a different font size to the text does not appear as an override.
You can clear character styles and formatting overrides when you apply a style. You can also clear overrides from a paragraph to which a style has been applied.