diff --git a/doc/src/module.tex b/doc/src/module.tex
index c8da646..d4e1e0a 100644
--- a/doc/src/module.tex
+++ b/doc/src/module.tex
@@ -132,6 +132,14 @@ The configuration language consists of top-level defining forms for
         \>\altz{}~ \tt(\syn{name} \syn{type}) \\
         \>\altz{}~ \tt((\arbno{\syn{name}}) \syn{type}) \\
    \syn{structure} \=\goesto{}~ \syn{name} \\
+        \>\altz{}~ \tt(modify \syn{structure} \arbno{\syn{modifier}}) \\
+        \>\altz{}~ \tt(subset \syn{structure} (\arbno{\syn{name}})) \\
+        \>\altz{}~ \tt(with-prefix \syn{structure} \syn{name}) \\
+   \syn{modifier} \=\goesto{}~ \tt(expose \arbno{\syn{name}}) \\
+        \>\altz{}~ \tt(hide \arbno{\syn{name}}) \\
+        \>\altz{}~ \tt(rename \arbno{(\syn{name}$_0$ \syn{name}$_1$)}) \\
+        \>\altz{}~ \tt(alias \arbno{(\syn{name}$_0$ \syn{name}$_1$)}) \\
+        \>\altz{}~ \tt(prefix \syn{name}) \\
 \end{tabbing}
 \caption{The configuration language.}
 \end{figure}
@@ -156,19 +164,58 @@ For building structures that export structures, there is a {\tt defpackage}
 Many other structures, such as record and hash table facilities, are also
  available in the \hack{} implementation.
 
-An {\tt access} clause specifies which bindings of names to structures
-will be visible inside the package body for use in {\tt structure-ref}
-forms.  {\tt structure-\ok{}ref} has the following syntax:
-\begin{tabbing}
-\qquad \syn{expression} \goesto{}~
-   \tt(structure-ref \syn{struct-name} \syn{name})
-\end{tabbing}
-The \syn{struct-name} must be the name of an {\tt access}ed structure,
-and \syn{name} must be something that the structure exports.  Only
-structures listed in an {\tt access} clause are valid in a {\tt
-structure-ref}.  If a package accesses any structures, it should
-probably open the {\tt structure-refs} structure so that the {\tt
-structure-ref} operator itself will be available.
+The \codemainindex{{modify}}, \codemainindex{{subset}}, and
+ \codemainindex{{prefix}} forms produce new
+ views on existing structures by renaming or hiding exported names.
+\code{Subset} returns a new structure that exports only the listed names
+ from its \syn{structure} argument.
+\code{With-prefix} returns a new structure that adds \syn{prefix}
+ to each of the names exported by the \syn{structure} argument.
+For example, if structure \code{s} exports \code{a} and \code{b},
+ then
+\begin{example}
+(subset s (a))
+\end{example}
+ exports only \code{a} and
+\begin{example}
+(with-prefix s p/)
+\end{example}
+exports \code{a} as \code{p/a} and \code{b} as \code{p/b}.
+
+Both \code{subset} and \code{with-prefix} are simple macros that
+ expand into uses of \code{modify}, a more general renaming form.
+In a \code{modify} structure specification the \syn{command}s are applied to
+ the names exported
+ by \syn{structure} to produce a new set of names for the \syn{structure}'s
+ bindings.
+\code{Expose} makes only the listed names visible.
+\code{Hide} makes all but the listed names visible.
+\code{Rename} makes each \syn{name}$_0$ visible as \syn{name}$_1$ 
+ name and not visible as \syn{name}$_0$ , while
+ \code{alias} makes each \syn{name}$_0$ visible as both \syn{name}$_0$ 
+ and \syn{name}$_1$.
+\code{Prefix} adds \syn{name} to the beginning of each exported name.
+The modifiers are applied from right to left.  Thus
+\begin{example}
+(modify scheme (prefix foo/) (rename (car bus))))
+\end{example}
+ makes \code{car} available as \code{foo/bus}..
+
+% Use modify instead of structure-ref.
+%
+%An {\tt access} clause specifies which bindings of names to structures
+%will be visible inside the package body for use in {\tt structure-ref}
+%forms.  {\tt structure-\ok{}ref} has the following syntax:
+%\begin{tabbing}
+%\qquad \syn{expression} \goesto{}~
+%   \tt(structure-ref \syn{struct-name} \syn{name})
+%\end{tabbing}
+%The \syn{struct-name} must be the name of an {\tt access}ed structure,
+%and \syn{name} must be something that the structure exports.  Only
+%structures listed in an {\tt access} clause are valid in a {\tt
+%structure-ref}.  If a package accesses any structures, it should
+%probably open the {\tt structure-refs} structure so that the {\tt
+%structure-ref} operator itself will be available.
 
 The package's body is specified by {\tt begin} and/or {\tt files}
 clauses.  {\tt begin} and {\tt files} have the same semantics, except