diff --git a/spec/formatting.md b/spec/formatting.md
index 8cf32fce35..7fe7e4a42a 100644
--- a/spec/formatting.md
+++ b/spec/formatting.md
@@ -7,3 +7,14 @@ when formatting a message for display in a user interface, or for some later pro
 
 The document is part of the MessageFormat 2.0 specification,
 the successor to ICU MessageFormat, henceforth called ICU MessageFormat 1.0.
+
+## Variable Resolution
+
+To resolve the value of a Variable,
+its Name is used to identify either a local variable,
+or a variable defined elsewhere.
+If a local variable and an externally defined one use the same name,
+the local variable takes precedence.
+
+It is an error for a local variable definition to
+refer to a local variable that's defined after it in the message.