How can I put HTML into flashcards?

You can add HTML for formatting by using the Source option found in the Advanced editor. However, if you want HTML tags to actually show up in your flashcards, that's a bit tricky, since they end up getting "rendered" in the browser or mobile flashcard player.

You can experiment with using "quotation marks" and other tricks to try to "escape" your HTML tags, but it can be finicky.