An Acronym for Internet Cache Protocol.
A widely implemented Protocol by which a WebProxy such as Squid can exchange hints about the existence of URLs with neighbouring caches. Caches exchange ICP queries and replies to gather information to use in selecting the most appropriate location from which to retrieve an object.
See also:
2 pages link to ICP:
lib/main.php:944: Notice: PageInfo: Cannot find action page
The
RFC: