[NTG-context] questions about indentation

Hi all, I'm using ConTeXt to typeset Chinese, and I am confused with indentation in ConTeXt. 1) I've searched the wiki and found several commands maybe relevant: \indentation, \indenting, \setupindentations, \setupindenting. My first question is what are the differences between "indentation" and "indenting" ? 2) In Chinese, most paragraphs start with an indentation of two characters. How to make the width of the indentation to be exactly two Chinese characters? I can achieve this approximately by using \setupindenting[big,yes] and \setupheads[indentnext=yes]. Thanks. Xiao Jianfeng