diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 732fd9aa4f..d65733ec4e 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -4008,6 +4008,55 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-TOOLCHAIN_HOSTS_TASKS'><glossterm>TOOLCHAIN_HOSTS_TASKS</glossterm>
+            <glossdef>
+                <para>
+                    This variable lists packages BitBake uses when it builds
+                    an SDK installer, which is used to extract and set up a
+                    cross-development environment.
+                    The packages specified by this variable are part of the
+                    toolchain set that runs on the
+                    <link linkend='var-SDKMACHINE'><filename>SDKMACHINE</filename></link>.
+                    When you build an SDK installer using BitBake, a set of
+                    default tasks apply.
+                    The tasks you specify here are added to those defaults.
+                </para>
+
+                <para>
+                    For background information on cross-development toolchains
+                    in the Yocto Project development environment, see the
+                    "<link linkend='cross-development-toolchain-generation'>Cross-Development Toolchain Generation</link>"
+                    section.
+                    For information on setting up a cross-development
+                    environment, see the
+                    "<ulink url='&YOCTO_DOCS_ADT_URL;#installing-the-adt'>Installing the ADT and Toolchains</ulink>"
+                    section in the Yocto Project Application Developer's Guide.
+                </para>
+            </glossdef>
+        </glossentry>
+
+        <glossentry id='var-TOOLCHAIN_TARGET_TASKS'><glossterm>TOOLCHAIN_TARGET_TASKS</glossterm>
+            <glossdef>
+                <para>
+                    This variable lists packages BitBake uses when it creates
+                    the target part of an SDK installer (i.e. the part built
+                    for the target hardware), which includes libraries and
+                    headers.
+                </para>
+
+                <para>
+                    For background information on cross-development toolchains
+                    in the Yocto Project development environment, see the
+                    "<link linkend='cross-development-toolchain-generation'>Cross-Development Toolchain Generation</link>"
+                    section.
+                    For information on setting up a cross-development
+                    environment, see the
+                    "<ulink url='&YOCTO_DOCS_ADT_URL;#installing-the-adt'>Installing the ADT and Toolchains</ulink>"
+                    section in the Yocto Project Application Developer's Guide.
+                </para>
+            </glossdef>
+        </glossentry>
+
         <glossentry id='var-TOPDIR'><glossterm>TOPDIR</glossterm>
             <glossdef>
                 <para>