When writing a kanji, some downstrokes have a clean end (such as in 木) while others end with a little hook (e.g. the center stroke of 小).
What are the names of such stroke tips?
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Sign up to join this community「はね」is what I always hear it referred to as.
A web search finds lots of sources to back this up:
http://www.bunkei.co.jp/bunkei-app/soragaki/common/images/function.jpg
http://www.y-adagio.com/public/standards/tr_fnttrm/fig7_7.gif
http://ja.wikipedia.org/wiki/%E7%AD%86%E7%94%BB
etc