diff --git a/doc/scsh-manual/syscalls.tex b/doc/scsh-manual/syscalls.tex
index 7dedfab..595acb4 100644
--- a/doc/scsh-manual/syscalls.tex
+++ b/doc/scsh-manual/syscalls.tex
@@ -2247,9 +2247,7 @@ I can't remember how \ex{set-priority} and \ex{priority} work, so no
 
 \defunx {user-login-name}{} \str
 \defunx {user-uid}{} \fixnum 
-\defunx {user-effective-uid}{} \fixnum
 \defunx {user-gid}{} \fixnum
-\defunx {user-effective-gid}{} \fixnum
 \defunx {user-supplementary-gids}{} {{\fixnum} list}
 \defunx {set-uid} {uid} \undefined
 \defunx {set-gid} {gid} \undefined
@@ -2259,6 +2257,22 @@ The \ex{set-uid} and \ex{set-gid} routines correspond to the {\Posix}
 \ex{\urlh{http://www.FreeBSD.org/cgi/man.cgi?query=setuid&apropos=0&sektion=0&manpath=FreeBSD+4.3-RELEASE&format=html}{setuid()}} and \ex{\urlh{http://www.FreeBSD.org/cgi/man.cgi?query=setgid&apropos=0&sektion=0&manpath=FreeBSD+4.3-RELEASE&format=html}{setgid()}} procedures.
 \end{desc}
 
+\defunx {user-effective-uid}{} \fixnum
+\defunx {set-user-effective-uid}{\fixnum} \undefined
+\defunx {with-user-effective-uid*} {\fixnum{} thunk}  {value(s) of thunk}
+\dfnx   {with-user-effective-uid}  {\fixnum{} . body} {value(s) of body} {syntax}
+\defunx {user-effective-gid}{} \fixnum
+\defunx {set-user-effective-gid}{\fixnum} \undefined
+\defunx {with-user-effective-gid*} {\fixnum{} thunk}  {value(s) of thunk}
+\dfnx   {with-user-effective-gid}  {\fixnum{} . body} {value(s) of body} {syntax}
+
+\begin{desc}
+  These forms manipulate the effective user/group IDs. Possible values
+  for setting this resource are either the real user/group ID or the
+  saved set-user/group-ID. The \texttt{with-...} forms perform the ususal
+  temprary assignment during the execution of the second argument. The
+  effective user and group IDs are thread-local.
+\end{desc}
 
 \defun {process-times} {} {[{\fixnum} {\fixnum} {\fixnum} \fixnum]}
 \begin{desc}
diff --git a/doc/scsh-manual/threads.tex b/doc/scsh-manual/threads.tex
index 3fd9177..ebc72bc 100644
--- a/doc/scsh-manual/threads.tex
+++ b/doc/scsh-manual/threads.tex
@@ -203,11 +203,12 @@ the global, asynchronous signals handlers into modular, synchronous
 sigevents. Concurrent programming also benefit from sigevents as every
 thread may chase down the sigevent chain separately.
 
-Scsh treats working directory, umask and environment as a thread-local
-resource. The initial value of the resources is determined by the way
-a thread is started: \texttt{spawn} assigns the initial values whereas
-\texttt{fork-thread} adopts the values of its parent. Here is a
-detailed description of the whole facility:
+Scsh treats the working directory, umask, environment, and the
+effective user/group ID as thread-local resources. The initial value
+of the resources is determined by the way a thread is started:
+\texttt{spawn} assigns the initial values whereas \texttt{fork-thread}
+adopts the values of its parent. Here is a detailed description of the
+whole facility:
 
 \begin{itemize}
 \item The procedures to access and modify the resources remain as