Today I learned a tesuji for settling a weak group from Michael Redmond’s commentary on Master(W) and bandari(B).
White has a weak group on the top needs to settle. The combination of 2 and 4 is a common tesuji.
What white wants is black to hane on the outside, white is planning to crosscut.
If black just extends, white can live on both sides.
If black ataris the stone, white can cut through and you can see the marked stone helps form a tiger mouth shape nicely.
So in the game black hanes from the inside, but white 2 is another tesuji and still manages to settle his group.