In a doublesided document, how can I suppress the chapter title marking 
in the header of the blank page that follows a chapter in which the text 
ends on a recto page? I do not want to suppress the header.

The following example shows the problem on pages 4 and 6. I notice that 
the Contents chapter does not exhibit this problem (page 2). But 
checking the source for /completecontent/ provides no useful 
information. Indeed, when I use /title/ instead of /chapter/, as done in 
strc-lis.mkvi, page 2 gets the marking as well!

    \setuppagenumbering [alternative=doublesided,location=]
    \setupheadertexts   [][{\it\getmarking[section]}]
                         [{\it\getmarking[chapter]}][]
    \setupheadertexts   [margin]
                         []
    [{\inframed[frame=off,leftframe=on,loffset=1em]
                             {\userpage}}]
    [{\inframed[frame=off,rightframe=on,roffset=1em]
                             {\userpage}}]
                         []
    \setuphead          [chapter]
                         [header=nomarking]

    \startbuffer[testt]
         \startchapter[title=Chapter]
             \startparagraph
                 \input ward
             \stopparagraph
             \dorecurse{\numexpr2*\recurselevel\relax}
                 {\startsection[title=Section]
                     \startparagraph
                         \input ward
                     \stopparagraph
                     \stopsection}
         \stopchapter
    \stopbuffer

    \starttext
    \completecontent
    \dorecurse{3}{\getbuffer[testt]}
    \startchapter[title={Chapter Last}]
         \input knuth
    \stopchapter
    \stoptext


-- 
Rik