Microsoft Word can detect formatting inconsistencies as you type and then mark them with a blue, wavy underline.You may want to have all the headings in a document formatted the exact same way, but you inadvertently formatted some of them differently. Word can detect these inconsistencies as you are typing and underline them with a blue wavy line to alert you.
On the Tools menu, click Options, and then click the Edit tab.
Under Editing options, select the Keep track of formatting check box, if it is not already selected.
Under Editing options, select the Mark formatting inconsistencies check box. Formatting inconsistencies will be marked with blue, wavy underlines.
In your document, right-click the blue, wavy underline where a formatting inconsistency has occurred.
Do one of the following: To correct the inconsistency, click the command that describes the inconsistency. To have Word remove the blue, wavy underline and not correct this inconsistency, click Ignore Once. To skip all occurrences of the inconsistency in the document, click Ignore Rule.