Be more explicit

README.md

 
 ## NOTICE
 
-Starting with versions 7.7.18 and 8.15.0, no new artifacts are being released in this repository. However, releases are being published as courtesy notifications to the users who have subscribed to the release feed of this repository. No further code changes will be published here.
+Starting with versions 7.7.18 and 8.15.0, no new artifacts are being released in this repository. However, releases are being published as courtesy notifications to the users who have subscribed to the release feed of this repository. No further code changes will be published here. The source code attached to Github releases in this repository reflects the state of code ***in this respository*** at time of release. It is ***NOT*** the source code of the corresponding Extended Maintenance release.
 
 ## Vaadin Framework has entered extended maintenance