Remove all uses of \sectcode; we can now use logical markup everywhere.
diff --git a/Doc/lib/libstrio.tex b/Doc/lib/libstrio.tex
index cf96dbb..9449dc2 100644
--- a/Doc/lib/libstrio.tex
+++ b/Doc/lib/libstrio.tex
@@ -1,4 +1,4 @@
-\section{Standard Module \sectcode{StringIO}}
+\section{Standard Module \module{StringIO}}
 \label{module-StringIO}
 
 \stmodindex{StringIO}