diff --git a/Changes.md b/Changes.md
index 53ff007f2..3e48bad6e 100644
--- a/Changes.md
+++ b/Changes.md
@@ -86,6 +86,11 @@ path:
 $(TARGET): myscript.py $(sort $(shell find my/python/lib -name '*.py'))
 	PYTHONPATH=my/python/lib:$$PYTHONPATH myscript.py -o $@
 ```
+### Stop using PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE directly {#PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE}
+
+Specify Framework Compatibility Matrix Version in device manifest by adding a `target-level`
+attribute to the root element `<manifest>`. If `PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE`
+is 26 or 27, you can add `"target-level"="1"` to your device manifest instead.
 
 ### Other envsetup.sh variables  {#other_envsetup_variables}
 
diff --git a/core/config.mk b/core/config.mk
index bf86fa8be..cfea0a50e 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -75,6 +75,7 @@ $(KATI_obsolete_var \
   ANDROID_EMULATOR_PREBUILTS \
   ANDROID_PRE_BUILD_PATHS \
   ,See $(CHANGES_URL)#other_envsetup_variables)
+$(KATI_obsolete_var PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE,Set FCM Version in device manifest instead. See $(CHANGES_URL)#PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE)
 
 CHANGES_URL :=