diff --git a/Isabelle_DOF-Example-I/document/lstisadof-manual.sty b/Isabelle_DOF-Example-I/document/lstisadof-manual.sty
index c9d2605..3229736 100644
--- a/Isabelle_DOF-Example-I/document/lstisadof-manual.sty
+++ b/Isabelle_DOF-Example-I/document/lstisadof-manual.sty
@@ -90,9 +90,7 @@
      ,enhanced jigsaw
      ,borderline west={2pt}{0pt}{isar!60!black}
      ,sharp corners
-     ,before skip balanced=0.5\baselineskip plus 2pt
-     % ,before skip=10pt
-     % ,after skip=10pt
+     %,before skip balanced=0.5\baselineskip plus 2pt % works only with Tex Live 2020 and later
      ,enlarge top by=0mm
      ,enhanced
      ,overlay={\node[draw,fill=isar!60!black,xshift=0pt,anchor=north
diff --git a/Isabelle_DOF-Ontologies/document/lstisadof-manual.sty b/Isabelle_DOF-Ontologies/document/lstisadof-manual.sty
index c9d2605..3229736 100644
--- a/Isabelle_DOF-Ontologies/document/lstisadof-manual.sty
+++ b/Isabelle_DOF-Ontologies/document/lstisadof-manual.sty
@@ -90,9 +90,7 @@
      ,enhanced jigsaw
      ,borderline west={2pt}{0pt}{isar!60!black}
      ,sharp corners
-     ,before skip balanced=0.5\baselineskip plus 2pt
-     % ,before skip=10pt
-     % ,after skip=10pt
+     %,before skip balanced=0.5\baselineskip plus 2pt % works only with Tex Live 2020 and later
      ,enlarge top by=0mm
      ,enhanced
      ,overlay={\node[draw,fill=isar!60!black,xshift=0pt,anchor=north
diff --git a/Isabelle_DOF/document/lstisadof-manual.sty b/Isabelle_DOF/document/lstisadof-manual.sty
index c9d2605..3229736 100644
--- a/Isabelle_DOF/document/lstisadof-manual.sty
+++ b/Isabelle_DOF/document/lstisadof-manual.sty
@@ -90,9 +90,7 @@
      ,enhanced jigsaw
      ,borderline west={2pt}{0pt}{isar!60!black}
      ,sharp corners
-     ,before skip balanced=0.5\baselineskip plus 2pt
-     % ,before skip=10pt
-     % ,after skip=10pt
+     %,before skip balanced=0.5\baselineskip plus 2pt % works only with Tex Live 2020 and later
      ,enlarge top by=0mm
      ,enhanced
      ,overlay={\node[draw,fill=isar!60!black,xshift=0pt,anchor=north