The standard of the Web is that a link appears in blue and underlined. However, not everyone follows the rules, perhaps as an misguided attempt for typographic coolness. This forum defaults the appearance of link text to blue text with no underlining:
Example 1: An unaltered link link text looks like this. It blends in with other text.
It works, but it is hard to distinguish the link text from the surrounding text of the post. The only clue is the color. By forcing an underlining of the link text, there is no doubt:
Example 2: A modified link looks like this. It stands out.
To force underlining, enclose the link text in underlining tags:
Example 3: [u]some-link-text[/u]. To sum up, this is how an underlined link would look before posting:
Example 4: [a href="http://some-site.com"][u]some-link-text[/u][/a]
SOFTWARE QUIRK NOTICE: To add to the confusion, while editing a post, previewing the post does underline all link text! So clicking Preview does not give you the true picture; the final effect can only be seen by clicking Save Changes.