manuals: document VIRTUAL-RUNTIME variables

Document the convention to use variables prefixed by VIRTUAL_RUNTIME.
Add references to the new term where possible.

Another reason is that such variables are recommended
in a warning issued by meta/classes-global/insane.bbclass

(From yocto-docs rev: db88c2021062c95fe49b54351952753390d45a6a)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Reported-by: Tim Orling <ticotimo@gmail.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/documentation/dev-manual/device-manager.rst b/documentation/dev-manual/device-manager.rst
index 0343d19b9c..49fc785fec 100644
--- a/documentation/dev-manual/device-manager.rst
+++ b/documentation/dev-manual/device-manager.rst
@@ -60,10 +60,10 @@ kernel.
 All devices created by ``devtmpfs`` will be owned by ``root`` and have
 permissions ``0600``.
 
-To have more control over the device nodes, you can use a device manager
-like ``udev`` or ``busybox-mdev``. You choose the device manager by
-defining the ``VIRTUAL-RUNTIME_dev_manager`` variable in your machine or
-distro configuration file. Alternatively, you can set this variable in
+To have more control over the device nodes, you can use a device manager like
+``udev`` or ``busybox-mdev``. You choose the device manager by defining the
+:term:`VIRTUAL-RUNTIME_dev_manager <VIRTUAL-RUNTIME>` variable in your machine
+or distro configuration file. Alternatively, you can set this variable in
 your ``local.conf`` configuration file::
 
    VIRTUAL-RUNTIME_dev_manager = "udev"