I would want to generate HTML, but in the example below, "html-test.tex", the index does not show in the file "html-test-export/html-test-div.html", and the source file \index{…}, gets in the HTML a black triangle. The index and links work fine in "html-test.pdf", though. — html-test.tex — \definefontfamily [mainface][math][stix] \setupbodyfont [mainface,10pt] \setupinteraction[state=start, click=yes, focus=standard, color=darkblue] \setupbackend[export=yes] % Exporting HTML/XML \defineregister [index] \setupregister [index] [indicator=no] \startchapter[title={Introduction}] Foobar\index{foobar} out of working order. \startbodymatter Foo\index{foo} or bar\index{bar}. \startbackmatter \completeindex \stopbackmatter \stoptext —