On the forums today?
Reading posts in the “General” forum today, and there are words in the text that will be a different color, and that are “double underscored”, ( make sense?), and SOMETIMES, when you hover over them, a “pop up” will appear.
The different colored text seem to function as a “hot link” as well.
Strange, I’ve never seen them on here, and no settings change on my computer or profile, to my knowledge.