2.1.89 Part 4 Section 2.3.2.38, u (Underline)
WordPad supports this element. WordPad supports only the w:val attribute of this element. On load, the values are handled in the following manner:
dotDash underlines become dash-dot underlines.
dotDotDash underlines become dash-dot-dot underlines.
WordPad maps the value "words" to the value "single".
All heavy underline values are mapped to the corresponding non-heavy values.