All text has an applied style
Confirms that all text has a Paragraph Style applied.
Paragraph Styles both ensure that the text is formatted consistently and help define the structure of a document. This check confirms that all the text in an InDesign document has a Paragraph Style applied.

To see a list of all the styles available to use in the document choose InDesign Window menu > Styles > Paragraph Styles
Fix this problem by selecting text that hasn't been formatted with a Paragraph Style (also known as styled with local formatting) and selecting the appropriate Paragraph Style name in the list.
Tip: To apply a Paragraph Style AND remove local formatting option/alt-click the appropriate Paragraph Style name in the list.