[NTG-context] References and formulae numbers in upshape

Hi everyone, I'm looking for an easy way to typeset all references produced by the \in command in upshape format (even in an italic paragraph for example). I tried with the 'left' option of \definereferenceformat, but without good results. I would also like to typeset all formulae numbers in upshape. I know Aditya posted about this a long time ago but I can't find the thread any more... Greetings, Morgan