Hi,
How to proceed so that the text of the head is not on the page with the table of contents and pages with the title of the chapter ?

Thanks

Fabrice

\setuplayout
[
    header=\lineheight,
    headerdistance=\lineheight,
]

\setupbackgrounds[header][text][bottomframe=on]

\setupheadertexts[{\getmarking[section]}][pagenumber]
                 [{\getmarking[chapter]}][pagenumber]

\setuppagenumbering[alternative=,location=]

\definestructureconversionset
[structure]
[numbers, Romannumerals, numbers, numbers, numbers]
[numbers]

\setupheads [sectionconversionset=structure]

\setuplist
[chapter]
[
   style=bold,
]

\starttext
\placelist[chapter,section][alternative=c]
\startchapter[title=Espaces probabilisés]
\startsection[title=Expérience aléatoire et univers]
    \dorecurse{5}{\input knuth}
\stopsection
\startsection[title=Événements]
    \dorecurse{5}{\input knuth}
\stopsection
\stopchapter
\startchapter[title=Variables aléatoires : généralités]
\startsection[title=Définition]
     \dorecurse{5}{\input knuth}
\stopsection
\startsection[title=Loi de probabilité d'une variable aléatoire]
     \dorecurse{5}{\input knuth}
\stopsection
\stopchapter
\stoptext