I've been trying to answer a question at SL. See attached file. It seems that this move has been played by Dosaku in those days but nowadays is no joseki. My preference would be to tenuki as White.

Any thoughts?

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Occupy Babel!

Tenuki, some extension on left, press at e16, some move at top side treating c15 approach lightly for now all seem plausible depending on the rest of the board. I guess b17 would mainly be played where the left side is important and black aims to play c14 with miai of extending on the side or connecting under at b15. There's a similar old joseki move of black 4-4, normal approach, one space low pincer, one space jump out, and then black jumps down to 2-4 aiming to link up to the pincer stone. That could happen in the sort of situation where white has big influence beyond the pincer stone so you fear the pincer stone dying on a big scale (and if white prevents the link up it's a good exchange to protect the 3-3 somewhat).