The soundex module is built-in, not standard.

"--" ==> "---"

Doc/lib/libsoundex.tex

-\section{Standard Module \sectcode{soundex}}
+\section{Built-in Module \sectcode{soundex}}
 \label{module-soundex}
-\stmodindex{soundex}
+\bimodindex{soundex}
 
 \renewcommand{\indexsubitem}{(in module soundex)}
 The soundex algorithm takes an English word, and returns an
@@ -10,7 +10,7 @@ soundex algorithm.
 
 Note that the soundex algorithm is quite simple-minded, and isn't
 perfect by any measure.  Its main purpose is to help looking up names
-in databases, when the name may be misspelled -- soundex hashes common
+in databases, when the name may be misspelled --- soundex hashes common
 misspellings together.
 
 \begin{funcdesc}{get_soundex}{string}

Doc/libsoundex.tex

-\section{Standard Module \sectcode{soundex}}
+\section{Built-in Module \sectcode{soundex}}
 \label{module-soundex}
-\stmodindex{soundex}
+\bimodindex{soundex}
 
 \renewcommand{\indexsubitem}{(in module soundex)}
 The soundex algorithm takes an English word, and returns an
@@ -10,7 +10,7 @@ soundex algorithm.
 
 Note that the soundex algorithm is quite simple-minded, and isn't
 perfect by any measure.  Its main purpose is to help looking up names
-in databases, when the name may be misspelled -- soundex hashes common
+in databases, when the name may be misspelled --- soundex hashes common
 misspellings together.
 
 \begin{funcdesc}{get_soundex}{string}