From http://www.w3schools.com (Copyright Refsnes Data)
The text-altitude property specifies the "height" for the ascent above the dominant baseline.
| Value | Description |
|---|---|
| use-font-metrics | Default. Uses a value for the height of the font above the baseline |
| length | Replaces the height value in the font with a specified length |
From http://www.w3schools.com (Copyright Refsnes Data)