ref-manual/variables.rst: document INHIBIT_UPDATERCD_BBCLASS

Fix [YOCTO #15753]

(From yocto-docs rev: 76a4dd5ce041b38f4cab714017a38b035d9530a3)

Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit 5f5a406d4acdfcbf655ac014d0d2807056f95291)
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

documentation/ref-manual/variables.rst

@@ -3916,6 +3916,25 @@ system and gives an overview of their function and contents.
          even if the toolchain's binaries are strippable, there are other files
          needed for the build that are not strippable.
 
+   :term:`INHIBIT_UPDATERCD_BBCLASS`
+      Prevents the :ref:`ref-classes-update-rc.d` class from automatically
+      installing and registering SysV init scripts for packages.
+
+      When a recipe inherits the :ref:`ref-classes-update-rc.d` class, init
+      scripts are typically installed and registered for the packages listed in
+      :term:`INITSCRIPT_PACKAGES`. This ensures that the relevant
+      services are started and stopped at the appropriate runlevels using the
+      traditional SysV init system.
+
+      To prevent the build system from adding these scripts and configurations
+      automatically, set the :term:`INHIBIT_UPDATERCD_BBCLASS` variable as follows::
+
+         INHIBIT_UPDATERCD_BBCLASS = "1"
+
+      By default, the value of :term:`INHIBIT_UPDATERCD_BBCLASS` is empty. Setting
+      it to "0" does not disable inhibition. Only the empty string will disable
+      inhibition.
+
    :term:`INIT_MANAGER`
       Specifies the system init manager to use. Available options are: