The Divi theme comes with an Accordion module which lets you present FAQs and other content in expandable boxes (or "toggles"). Open accordion toggles display a close icon on the right hand-side of the title. But there isn't currently an option to display an additional icon next to the title itself. If you'd like to do so, here's how you can:
Add an Accordion Title Icon using CSS
First, give your accordion a CSS ID (e.g. "my-accordion" ) at:
Accordion Settings > Advanced > CSS ID & Classes > CSS ID
Then you can set an icon for the accordion titles using CSS such as this:
#my-accordion .et_pb_toggle_title:after {
content: '\70';
font-family: 'ETModules';
float:left;
margin-right: 1em;
}Related Post: Adding CSS to the Divi Theme
This example CSS will add an "information" icon next to each toggle title, like so:
To use a different icon, visit the Elegant Icon Font page and get the code for your desired icon, replacing p with \70,  with \e007, etc. in the CSS above.
Thank you, that's exactly what I was looking for.
Very glad to hear it helped, Rolf. Thanks!