Concealed hands,
clearly explained.
That little C on the card can bring up a lot of questions. Get clear answers about calling the winning tile, using jokers, and keeping your hand concealed.

A reference to keep beside your card.
A little clarity for your next game.
Find the answer quickly.
A one-page reference for what you can call, where jokers belong, and how exchanges fit.
See the difference.
Real tile examples and a clear explanation of C and X on the card.
Try five table situations.
Practice the decisions, then check the answers and the reason behind each one.
You do not have to remember every detail at once. Start with the quick reference, then work through the examples at your own pace.