Remove all \bcode / \ecode cruft; this is no longer needed. See previous
checkin of myformat.sty.
Change "\renewcommand{\indexsubitem}{(...)}" to "\setindexsubitem{(...)}"
everywhere.
Some other minor nits that I happened to come across.
diff --git a/Doc/lib/liberrno.tex b/Doc/lib/liberrno.tex
index 2c45266..cf5f854 100644
--- a/Doc/lib/liberrno.tex
+++ b/Doc/lib/liberrno.tex
@@ -1,7 +1,7 @@
\section{Standard Module \sectcode{errno}}
\stmodindex{errno}
-\renewcommand{\indexsubitem}{(in module errno)}
+\setindexsubitem{(in module errno)}
This module makes available standard errno system symbols.
The value of each symbol is the corresponding integer value.