--- Makefile	(revision 523631)
+++ Makefile	(working copy)
@@ -9,6 +9,9 @@ 
 MAINTAINER=	mono@FreeBSD.org
 COMMENT=	Mono framework to create extensible applications
 
+DEPRECATED=	This framework has been deprecated upstream since 2018 and is no longer maintained.
+EXPIRATION_DATE=	2020-04-20
+
 LICENSE=	MIT
 
 USE_GITHUB=	yes