Abstract: A method, system and related apparatus are described, the system comprising a caching-capable element which is part of a data network, which receives a request from a downstream client device, the request including a content request, the content request including a Universal Resource Identifier (URI) and an explicit caching request, the caching request includes a unique content identifier which is independent of the URI, and optional expiration date information, a comparator included at the caching-capable element which compares the caching request against the existing cached content, and if the requested content is cached then the caching-capable element forwards the cached copy of the requested content to the client device, and if the requested content is not cached, then the caching-capable element forwards the request to a further upstream device, and, upon reception of the requested content from the further upstream device, returns the requested content to the requesting downstream device, and caches the