3-4 point low approach, upper attachment
The upper attachment at almost forces . Unlike the 4-4 point low approach upper attachment joseki, there is little for a side switch to occur in this joseki. Typical followups include a and b.
Black can also cross-cut at .
The end result is that black has better influence outside, but white is very thick and cannot be attacked. For more on this joseki, see attach-crosscut corner patterns.