You can undo all formatting that has not been made by styles in a few steps.
Formati rekte kaj nerekte
A style is a set of formatting attributes, grouped and identified by a name (the style name). When you apply a style to an object, the object is formatted with the set of attributes of the style. Several objects of same nature can have the same style. As consequence, when you change the set of formatting attributes of the style, all objects associated with the style also change their formatting attributes accordingly. Use styles to uniformly format a large set of paragraphs, cells, and objects and better manage the formatting of documents.
When you do not use styles, and apply formatting attributes to parts of text directly, this is called Direct formatting (also called manual formatting). The formatting is applied only to the selected area of the document. If the document has several paragraphs, frames, or any other object, you apply direct formatting on each object. Direct formatting is available with the Format menu and with the Formatting toolbar.
A direct formatting attribute applied on a object overrides the corresponding attribute of the style applied to the object.