Use \withsubitem{} for indexing extra-module functions.
diff --git a/Doc/lib/libposixfile.tex b/Doc/lib/libposixfile.tex
index a8a6d71..9ab584b 100644
--- a/Doc/lib/libposixfile.tex
+++ b/Doc/lib/libposixfile.tex
@@ -7,7 +7,7 @@
\emph{Note:} This module will become obsolete in a future release.
The locking operation that it provides is done better and more
portably by the \function{fcntl.lockf()} call.%
-\index{lockf()@\idxcode{lockf()} (in module fcntl)}
+\withsubitem{(in module fcntl)}{\ttindex{lockf()}}
This module implements some additional functionality over the built-in
file objects. In particular, it implements file locking, control over
@@ -15,7 +15,8 @@
The module defines a new file object, the posixfile object. It
has all the standard file object methods and adds the methods
described below. This module only works for certain flavors of
-\UNIX{}, since it uses \function{fcntl()} for file locking.
+\UNIX{}, since it uses \function{fcntl.fcntl()} for file locking.%
+\withsubitem{(in module fcntl)}{\ttindex{fcntl()}}
To instantiate a posixfile object, use the \function{open()} function
in the \module{posixfile} module. The resulting object looks and
diff --git a/Doc/libposixfile.tex b/Doc/libposixfile.tex
index a8a6d71..9ab584b 100644
--- a/Doc/libposixfile.tex
+++ b/Doc/libposixfile.tex
@@ -7,7 +7,7 @@
\emph{Note:} This module will become obsolete in a future release.
The locking operation that it provides is done better and more
portably by the \function{fcntl.lockf()} call.%
-\index{lockf()@\idxcode{lockf()} (in module fcntl)}
+\withsubitem{(in module fcntl)}{\ttindex{lockf()}}
This module implements some additional functionality over the built-in
file objects. In particular, it implements file locking, control over
@@ -15,7 +15,8 @@
The module defines a new file object, the posixfile object. It
has all the standard file object methods and adds the methods
described below. This module only works for certain flavors of
-\UNIX{}, since it uses \function{fcntl()} for file locking.
+\UNIX{}, since it uses \function{fcntl.fcntl()} for file locking.%
+\withsubitem{(in module fcntl)}{\ttindex{fcntl()}}
To instantiate a posixfile object, use the \function{open()} function
in the \module{posixfile} module. The resulting object looks and