Actually, I was the Real One Wiki

Kiera's Cheat Sheet is a little sheet of paper that contains talking points and essential information commonly known amongst the noble ladies. It was created by the female knights in the novel and by Daphne Shore in the manhwa.

Joshua White: His main song is the one he performed at the graduation concert, 'Evening Glow of the Wolf River'. People will treat you like a fool if you don't know this, so act like you do!

Etretate's Boutique: A boutique opened by the designer from Julie's Boutique after having a huge fight with Madam Vivian. Although it's a popular store these days, there could be a fight between Julie's Boutique and Etretate's, so do not bring this up.

Mamonde: A record-breaking, new big production that had a full house 3 times in a row. If you don't know this you will be treated as an unrefined person, so pretend to know.