Update 4.7-rc.md

doc/4.7-rc.md

@@ -99,7 +99,18 @@ You might want to spot-check a few URLs to ensure the branches were published, e
    * Click "Build with parameters"
    * For the branch name, enter your chosen `4.7.X-rc`.
 
-## 5: Bump version number on `master` to  `4.7.Y`
+## 5: Enable branch protection
+
+To prevent someone from accidentally deleting the new RC branch, enable protection:
+
+ * https://github.com/civicrm/civicrm-core/settings/branches
+ * https://github.com/civicrm/civicrm-packages/settings/branches
+ * https://github.com/civicrm/civicrm-backdrop/settings/branches
+ * https://github.com/civicrm/civicrm-drupal/settings/branches
+ * https://github.com/civicrm/civicrm-joomla/settings/branches
+ * https://github.com/civicrm/civicrm-wordpress/settings/branches
+
+## 6: Bump version number on `master` to  `4.7.Y`
 
 The original branch, "master", should continue development with the next version, e.g. "4.7.Y".