diff --git a/configure b/configure
index 1fe78bcf..d4989499 100755
--- a/configure
+++ b/configure
@@ -314,14 +314,34 @@ an installation prefix other than \`${PREFIX_DEFAULT}' using \`--prefix',
 for instance \`--prefix=\${HOME}'.
 
 For better control, use the options below.
+Note: options marked as \`ignored' are recognised, but not acted upon, as
+they make no sense for crosstool-NG, or they are not implemented yet.
 
 Fine tuning of the installation directories:
   --bindir=DIR            user executables [PREFIX/bin]
   --libdir=DIR            object code libraries [PREFIX/lib]
   --docdir=DIR            info documentation [PREFIX/share/doc]
   --mandir=DIR            man documentation [PREFIX/share/man]
+  --infodir=DIR           info documentation [DATAROOTDIR/info] (ignored)
+  --datadir=DIR           read-only architecture-independent data [DATAROOTDIR]
+                          (ignored)
+  --sysconfdir=DIR        read-only single-machine data [PREFIX/etc] (ignored)
+  --localstatedir=DIR     modifiable single-machine data [PREFIX/var] (ignored)
+
+Program names:
+  --program-prefix=PREFIX            prepend PREFIX to installed program names
+                                     (ignored)
+
+System types:
+  --build=BUILD     configure for building on BUILD [guessed] (ignored)
+  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
+                    (ignored)
 
 Optional Features:
+  --enable-shared[=PKGS]  build shared libraries [default=yes] (ignored)
+  --enable-static[=PKGS]  build static libraries [default=yes] (ignored)
+
+Optional Packages:
   --with-install=PATH     Specify the full PATH to GNU install
   --with-make=PATH        Specify the full PATH to GNU make >= 3.80
   --with-grep=PATH        Specify the full PATH to GNU grep