4-4 point low approach, two-space high pincer with side stone
In the presence of ,
is a pincer that works in a way that is quite similar to the pincer at a, which has to a great extent replaced
in pro games.
For White's reply at b see catenaccio joseki. The hazama tobi at c is the other common possibility.
The usual way for White to play is the immediate 3-3 invasion. is indicated here, because of
.
may be at a, b or c. At c is often seen in the West because of an 'old information' effect: the pros have hardly played this since 1975, but it's still in the books in English.
Allowing white to cut at as a threat to break through could lead to this position. Responding to
with a counter hane at a asks for the stone tower tesuji. Black can avoid the stone tower but it will still give w a larger corner, quite likely in sente, for no compensation.