diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index f72bbd0e05..e34843512a 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -7931,6 +7931,39 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
BPN variable).
MLPREFIX gets set when a prefix has been
added to PN.
+
+ The "ML" in MLPREFIX stands for
+ "MultiLib".
+ This representation is historical and comes from
+ a time when nativesdk was a suffix
+ rather than a prefix on the recipe name.
+ When nativesdk was turned into a
+ prefix, it made sense to set
+ MLPREFIX for it as well.
+
+
+
+
+ To help understand when MLPREFIX
+ might be needed, consider when
+ BBCLASSEXTEND
+ is used to provide a nativesdk version
+ of a recipe in addition to the target version.
+ If that recipe declares build-time dependencies on tasks in
+ other recipes by using
+ DEPENDS,
+ then a dependency on "foo" will automatically get rewritten
+ to a dependency on "nativesdk-foo".
+ However, dependencies like the following will not get
+ rewritten automatically:
+
+ do_foo[depends] += "recipe:do_foo"
+
+ If you want such a dependency to also get transformed,
+ you can do the following:
+
+ do_foo[depends] += "${MLPREFIX}recipe:do_foo"
+