User blog:SneakyBoiHasRan129874/How can I make "if" function?

On a wiki that I'm admin on, I've been editing an infobox to make it so that one of the senctions would appear only if it was mentioned in the page the template was put in. I'm not very familiar with the CSS3 language but I do know that the right statement for that is using in the code. Though I couldn't figure out how to do it as the default templates use the parametre. I'd appreciate if someone could assist me in this.