diff --git a/icu4c/source/i18n/unicode/measunit.h b/icu4c/source/i18n/unicode/measunit.h
index f8168c23f96..4104f40d1e1 100644
--- a/icu4c/source/i18n/unicode/measunit.h
+++ b/icu4c/source/i18n/unicode/measunit.h
@@ -375,14 +375,15 @@ class U_I18N_API MeasureUnit: public UObject {
     MeasureUnit(MeasureUnit &&other) noexcept;
 
     /**
-     * Construct a MeasureUnit from a CLDR Unit Identifier, defined in UTS 35.
-     * Validates and canonicalizes the identifier.
+     * Construct a MeasureUnit from a CLDR Core Unit Identifier, defined in UTS
+     * 35. (Core unit identifiers and mixed unit identifiers are supported, long
+     * unit identifiers are not.) Validates and canonicalizes the identifier.
      *
      * <pre>
      * MeasureUnit example = MeasureUnit::forIdentifier("furlong-per-nanosecond")
      * </pre>
      *
-     * @param identifier The CLDR Unit Identifier
+     * @param identifier The CLDR Unit Identifier.
      * @param status Set if the identifier is invalid.
      * @draft ICU 67
      */
diff --git a/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java b/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java
index 26117eb86e1..e05400da8b9 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java
@@ -412,8 +412,9 @@ public class MeasureUnit implements Serializable {
     }
 
     /**
-     * Construct a MeasureUnit from a CLDR Unit Identifier, defined in UTS 35.
-     * Validates and canonicalizes the identifier.
+     * Construct a MeasureUnit from a CLDR Core Unit Identifier, defined in UTS
+     * 35. (Core unit identifiers and mixed unit identifiers are supported, long
+     * unit identifiers are not.) Validates and canonicalizes the identifier.
      *
      * Note: dimensionless <code>MeasureUnit</code> is <code>null</code>
      *