diff --git a/BLFS/envars.conf b/BLFS/envars.conf
index 8775faf..a94c0fd 100644
--- a/BLFS/envars.conf
+++ b/BLFS/envars.conf
@@ -65,17 +65,38 @@ export XDG_DATA_DIRS=/usr/share:/usr/local/share
 
 #======== KDE envars =============
 
+# Refer to `Chapter 27. Introduction->KDE Pre-installation Configuration'
+# for rationale. We use envars.conf instead of /etc/profile.d. But if you
+# install into a different prefix, you'll need to update ld.so.conf and
+# man-db.conf, too.
+
 #--- Installation prefix
-export KDE_PREFIX=/usr
+export KDE4_PREFIX=/usr
 
-#--- If you want to install KDE on a non standart prefix, uncomment
-#    the next export lines and edit it if needed.
-#    See also the KDE Pre-installation Configuration HTML page for
-#    aditional required commands.
-#export PATH=$PATH:$KDE_PREFIX/bin
-#export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$KDE_PREFIX/lib/pkgconfig
+#--- If you want to install KDE on a non standard prefix, uncomment
+#    the next lines and edit them it as needed.
+#KDE4_PREFIX=/opt/kde4
+#KDE4DIR=$KDE4_PREFIX
+#KDEDIR=$KDE4_PREFIX
 
+#PATH=$PATH:$KDE4_PREFIX/bin
+#if [ -z PKG_CONFIG_PATH ]; then
+#  PKG_CONFIG_PATH=$KDE4_PREFIX/lib/pkgconfig:$KDE4_PREFIX/share/pkgconfig
+#else
+#  PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$KDE4_PREFIX/lib/pkgconfig:$KDE4_PREFIX/share/pkgconfig
+#fi
+#if [ -z XDG_DATA_DIRS ]; then
+#  XDG_DATA_DIRS=$KDE4_PREFIX/share
+#else
+#  XDG_DATA_DIRS=$XDG_DATA_DIRS:$KDE4_PREFIX/share
+#fi
+#if [ -z XDG_CONFIG_DIRS ]; then
+#  XDG_CONFIG_DIRS=/etc/kde4/xdg
+#else
+#  XDG_CONFIG_DIRS=$XDG_DATA_DIRS:/etc/kde4/xdg
+#fi
 
+#export KDE4_PREFIX KDE4DIR KDEDIR
 
 #======== Optimizations =============