[MarkFL]

Most HTML elements can be given a "title" attribute that can contain text that is displayed by a user's browser in a "popup"element. You could create a custom BB Code to do that...say you wanted to used [title][/title] tags, then the replacement code could be:

<span title="{option}" style="border-bottom: 1px dotted #000; cursor: help">{param}</span>

And then when posting, your users could enter something like:

[title=Tooltip text is here]displayed text is here[/title]

And the "displayed text is here" would have a dotted border along the bottom to indicate it has a tooltip, and when hovering the mouse cursor over this text, the cursor would change to the help cursor and the text ""Tooltip text is here" will display in the popup.