[html] Alternative to the HTML Bold tag

If the text's meaning is semantically strong, use the strong element. If not, use a semantic named class (one that clearly shows the meaning of the element, don't mix presentation and data by calling it bold etc) and reference it in your CSS.

HTML

<span class="important-message">I'm important!</span>

CSS

.important-message {
   font-weight: bold;
}

Some people still use the b element as a presentational hook, but it hasn't been deprecated, though most people favour the strong element nowadays. Just make sure they are used correctly.