The text-underline-position property is used in CSS and certain HTML elements. This property specifies the default position of the underline which is set using the CSS text-decoration:underline;.

Values

• auto - Underline decoration appears above the text if the HTML lang attribute for an underlined element is set to ja (Japanese) and the CSS writing-mode property is set to tb-rl. Otherwise, the underline decoration appears below the content.
• auto-pos - IE's documentation says that this value behaves the same as auto.
• below - Underline decoration will appear below the enclosed content.
• above - Underline decoration will appear above the enclosed content.

HTML example:

<span style="text-decoration:underline; text-underline-position:auto;">Check out the underline.</span>

CSS example:

h1 {
    text-decoration:underline;
    text-underline-position:auto;
}