[NTG-context] Why do I have to enclose \rawcounter in braces in this MWE ?

25 Sep 2018

      Hello list,

Why do I have to enclose \rawcountervalue in braces to get this MWE
compiled ?  

   \definecounter[fiche][way=bytext]
   \setupheadertexts[Fiche méthodologique N.{\rawcountervalue[fiche]} ][][][]

   \starttext
   \setcounter[fiche][2]

   \starttitle[title={Un essai}]

   \startsection[title={Un premier chapitre}]
   voilà
   \stopsection

   \startsubsection[title={Un deuxième}]
   tak jest.
   \stopsubsection

   \stoptitle

   \stoptext

Thanks,

Damien Thiriet