diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 2507d4b520..8ff0d671d1 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -10042,6 +10042,23 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
PREFERRED_PROVIDER
variable is used to select which particular recipe
provides a virtual target.
+
+ A corresponding mechanism for virtual runtime
+ dependencies (packages) exists.
+ However, the mechanism does not depend on any special
+ functionality beyond ordinary variable assignments.
+ For example,
+ VIRTUAL-RUNTIME_dev_manager
+ refers to the package of the component that manages
+ the /dev directory.
+
+ Setting the "preferred provider" for runtime
+ dependencies is as simple as using the following
+ assignment in a configuration file:
+
+ VIRTUAL-RUNTIME_dev_manager = "udev"
+
+