Hi, I'm not sure if my message on the regular list got noticed but \setuphead[chapter][referenceprefix=+] doesn't work in LMTX and MkIV. Below is a fix the LMTX version (I used MkII as reference): \def\strc_sectioning_set_reference_prefix {\ifempty\currentstructurereferenceprefix % nothing \orelse\ifx\currentstructurereferenceprefix\m_strc_references_prefix_yes - \global\advance\prefixcounter \plusone % temp here - \setupglobalreferenceprefix[\the\prefixcounter]% + \ifempty\currentstructurereference + \global\advance\prefixcounter \plusone % temp here + \setupglobalreferenceprefix[\the\prefixcounter]% + \else + \setupglobalreferenceprefix[\currentstructurereference]% + \fi \orelse\ifx\currentstructurereferenceprefix\m_strc_references_prefix_nop \setupglobalreferenceprefix[]% \else \setupglobalreferenceprefix[\currentstructurereferenceprefix]% \fi \glet\currentstructurereferenceprefix\referenceprefix} Wolfgang