mention cache_object scheme removal effects

Author: yadij

docs/Features/CacheManager/CacheManagerCgi.md

@@ -1,15 +1,19 @@
 # This Cache Manager CGI tool
 
 This is tool that provides basic management capabilities of a Squid
-server through a HTML user interface.
+server through an HTML user interface.
 As every
 [Common_Gateway_Interface](http://en.wikipedia.org/wiki/Common_Gateway_Interface),
 software, it requires an HTTP server to make it really run.
 
-The communication with the Squid server is made up using the
-[Cache Object Protocol](/Features/CacheManager/CacheObjectScheme), that provides access to the underlying
+The communication with the Squid server is made using the
+[`cache_object` URL scheme](/Features/CacheManager/CacheObjectScheme), that provides access to the underlying
 [Cache Manager](/Features/CacheManager).
 
+:warning: 
+With the removal of [`cache_object` support](/Features/CacheManager/CacheObjectScheme) in [Squid-7](/Releases/Squid-7)
+releases of this tool older than v3.2 will no longer work.
+
 More information is currently available at
 [Features/CacheManager](/Features/CacheManager).