Use the ID/Class/Element option if you want to display changes on the pages of your website containing an element linked to a specific ID or class, whose presence cannot be determined by a URL. It is useful for targeting a set of pages that don't share a structure.
For example, you want to create a specific carousel on the homepage of your website for clients who have the gold membership.
The only element that differentiates a gold member from a “standard” member is an icon located in the header of your website. Gold members have a specific menu/section listing all their advantages. On the website, this section is coded with an ID called #menu-gold.
In this case, you need to target the pages that contain this specific ID.
To do so, choose ID/Class/Element, select Include > ID and select the relevant ID from the drop-down list.
For more information, refer to Target a test according to the presence of a specific CSS class or ID.