Gomoto wrote:
"b" is a vulgar play, for sure.
I took a quick look at http://ps.waltheri.net , which gives it a win rate of 0.
Gomoto wrote:
Continuation
However, this kind of sequence is not all that unusual.
Waltheri shows only two pro games with this pattern. (Its database is limited, OC.) White continued at "a" in one, at "b" in the other. A look at both games, however, revealed a problem with Waltheri's win rates, that I have noticed before. Black won both games, not White.
Perhaps the "problem" is the cut,
. I looked in the Suzuki-Kitani Small Joseki Dictionary, which does not show the cut, but has one diagram where Black plays "a" instead, which they did not like for Black. Waltheri shows one game with that pattern. Black won it, too. 
Maybe the vulgar play is OK.
Edit:
The jump,
, is an attractive play. Waltheri reports 4 games with this pattern, but one of them looks like a duplicate. Black won 2 games to White's 1.The vulgar push,
, occurs infrequently, so I don't think that we can call it joseki. If we take this position as emblematic, we can see that there are two problems with Black's position. The first is that Black is confined to the corner. The second, perhaps more serious problem is that the 
stones are floating. OC, as the actual games indicate, that is not a fatal flaw. But I think that the health of the stones is a very important factor in whether to play or not.
? I am guessing