underline-style Appearance of the Underline
Style of underline to be used (for example, “single”, “double”, “dashed”).
This attribute was added to preserve this information when a publisher supplies it. The use of the attribute does not guarantee that the display will produce the formatting requested.
OPTIONAL on element: <underline>
|Text, numbers, or special characters||The style of underlining requested; for example, “double” would mean underlined by two rules, very close together.|
|Restriction||This is an optional attribute; there is no default.|