Inserting a line using keyboard shortcuts
Type the following characters and then press Enter or Return to insert lines:
To insert a plain single line, type three hyphens (—).
To insert a plain double line, type three equal signs (===).
To insert a dotted line, type three asterisks (***).
To insert a bold single line, type three underscore (___).
To insert a wavy line, type three tildes (~~~).
To insert a triple line, type three number signs or hash tags (###).
To remove these lines, select the paragraph with the line, click the Borders button on the Home tab and select No Border.