diff --git a/INSTALL b/INSTALL
index e490d22d3..dedf236a8 100644
--- a/INSTALL
+++ b/INSTALL
@@ -190,20 +190,23 @@ corresponding platform are not needed for the platform in question.
 
   - For host
     1. --host= to autoconf name of host.
-    2. CC= for gcc able to compile for host
-    3. HOST_CFLAGS= for C options for host.
-    4. HOST_CPPFLAGS= for C preprocessor options for host.
-    5. HOST_LDFLAGS= for linker options for host.
-    6. PKG_CONFIG= for pkg-config for host (optional).
-    7. Libdevmapper if any must be in standard linker folders (-ldevmapper) (optional).
-    8. Libfuse if any must be in standard linker folders (-lfuse) (optional).
-    9. Libzfs if any must be in standard linker folders (-lzfs) (optional).
-    10. Liblzma if any must be in standard linker folders (-llzma) (optional).
+    2. CC= for gcc able to compile for host.
+    3. CFLAGS= for C options for host.
+    4. HOST_CC= for gcc able to compile for host.
+    5. HOST_CFLAGS= for C options for host.
+    6. HOST_CPPFLAGS= for C preprocessor options for host.
+    7. HOST_LDFLAGS= for linker options for host.
+    8. PKG_CONFIG= for pkg-config for host (optional).
+    9. Libdevmapper if any must be in standard linker folders (-ldevmapper) (optional).
+    10. Libfuse if any must be in standard linker folders (-lfuse) (optional).
+    11. Libzfs if any must be in standard linker folders (-lzfs) (optional).
+    12. Liblzma if any must be in standard linker folders (-llzma) (optional).
+    Note: The HOST_* variables override not prefixed variables.
 
   - For target
     1. --target= to autoconf cpu name of target.
     2. --with-platform to choose firmware.
-    3. TARGET_CC= for gcc able to compile for target
+    3. TARGET_CC= for gcc able to compile for target.
     4. TARGET_CFLAGS= for C options for target.
     5. TARGET_CPPFLAGS= for C preprocessor options for target.
     6. TARGET_CCASFLAGS= for assembler options for target.
@@ -212,6 +215,10 @@ corresponding platform are not needed for the platform in question.
     9. TARGET_STRIP= for strip for target.
     10. TARGET_NM= for nm for target.
     11. TARGET_RANLIB= for ranlib for target.
+    Note: If the TARGET_* variables are not specified then they will default
+          to be the same as the host variables. If host variables are not
+          specified then the TARGET_* variables will default to be the same
+          as not prefixed variables.
 
   - Additionally for emu, for host and target.
     1. SDL is looked for in standard linker directories (-lSDL) (optional)
diff --git a/configure.ac b/configure.ac
index 3eda9a5a2..7c10a4db7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -26,10 +26,13 @@ dnl This is necessary because the target type in autoconf does not
 dnl describe such a system very well.
 dnl
 dnl The current strategy is to use variables with no prefix (such as
-dnl CC, CFLAGS, etc.) for the host type, variables with prefix "BUILD_"
-dnl (such as BUILD_CC, BUILD_CFLAGS, etc.) for the build type and variables
-dnl with the prefix "TARGET_" (such as TARGET_CC, TARGET_CFLAGS, etc.) are
-dnl used for the target type. See INSTALL for full list of variables.
+dnl CC, CFLAGS, etc.) for the host and target type, variables with
+dnl prefix "BUILD_" (such as BUILD_CC, BUILD_CFLAGS, etc.) for the
+dnl build type, variables with prefix "HOST_" (such as HOST_CC,
+dnl HOST_CFLAGS, etc.) for the host type and variables with the prefix
+dnl "TARGET_" (such as TARGET_CC, TARGET_CFLAGS, etc.) are used for
+dnl the target type. See INSTALL for full list of variables and
+dnl description of the relationships between them.
 
 AC_INIT([GRUB],[2.05],[bug-grub@gnu.org])