[NTG-context] How to make empty pages by default empty?

Hi, I guess this is very likely a FAQuestion but nevertheless I couldn't find the answer: When a new sectionblock or a chapter (page=right) is starting and ConTeXt is forced to add before that a left empty page then this empty page has naked pagenumber. So what is the code to make empty pages by default empty (no header, no pagenumber)? Sorry for this probably silly question, but I truely might be happy for an answer. Thanks, Steffen.