Historically there was an HTML underline tag, which was used much like the bold (<b>) and italic (<i>) tags.
Here’s how the underline tags have been used:
Example text with an <u>underlined</u> word
Example text with an underlined word
The default CSS styling for the underline <u> tag is to add an underline, as shown above.
To underline a section of website content using CSS, for example underlining the class of uline.
.uline {
text-decoration: underline;
}
I have also seen content editors implement the underline not with the addition of the <u> using the above CSS with a <span> HTML tag and appropriate style settings. for example
<span style="text-decoration:underline">Underlined text</span>
References
W3 Schools: HTML <u> tag
W3 Schools CSS text decoration
