Web site found in a quick web search:
http://www.karateforums.com/archive/.../view_previous
Slip punch - a short punch that travels to the side across your body (usually a short strike to the body from a sideways stance/situation as in the Neifanchi katas)
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Mostly looks like technique is stop halfway through "crane stretches wings".
From crane style kung fu, but clearly it appears to be a snake kung fu technique since the other arm is couched, from underneath even a knife hand attack would be possibly the purpose, but short range cross handed, if I was looking at the correct web pages pictures. Similar to placing hands in sand, but horizontal instead of vertical. Interesting. Karate seems to be most common title of web sites that claim this technique, from my short search. Of course kung fu and karate have a lot of cross knowledge/history & techniques.