Hi Hans, It seems that in the latest beta, ConTeXt ver: 2010.06.18 11:26 MKIV the description environment is broken: the header does not change after the first invocation of the defined description: in the following minimal example the first invocation uses Lemma, and the second and third one remain with Lemma instead of Theorem or Corollary. However with mkii everything works fine. Thanks for your attention and best regards: OK %%%% bug-description.tex \definedescription[Proclaim][% headstyle={\tfa\bi}, style=normal, location=hanging, width=broad, grid={broad,high} ] \starttext \startProclaim{Lemma} This is a lemma. \stopProclaim \startProclaim{Theorem} This is a theorem. \stopProclaim \startProclaim{Corollary} This is a corollary. \stopProclaim \stoptext