If no content negotiation is in place, serve a canonical representation (generic resource) of the content at http://example.com/ubiquity/resource

With that same URI, use HTTP content-negotiation, along with the correct HTTP VARY headers to serve up the appropriate representation at access time. Ensure that the VARY headers capture the right parameters that were used to choose the representation that is being served — this is important for correct behavior when using cacheing proxies.

As an alternative to the previous step, arrange for the server to generate an HTTP 302 (Found) redirect to automatically serve up http://example.com/ubiquity/representation_i when http://example.com/ubiquity is accessed by user-agent_i. This form of redirect involves an extra client/server round-trip, and may therefore be suboptimal for mobile devices. This is a temporary redirect; the accessing user-agent should continue to use the canonical URI when creating bookmarks, or emailing URI. Finally, note that to optimize link traversal out of the resulting document, the content provider might wish to rewrite relative links to point at the specific resource. This will ensure that later uses of the URI results in expected end-user results; e.g., In the following scenario: Cell-phone user emails link Recipiant opens message on a desktop Clicks on the link The user following the link from inside the email message on a desktop browser should receive the desktop version, and not the mobile version. Notice that passing around the canonical URI is critical in achieving this behavior.

Additionally, contrast this solution with using HTTP content-negotiation with VARY headers; using a redirect to the URI as a specific resource has the advantage of freezing all parameters that were used to choose that representation into the URI.

Use linking mechanisms provided by the representation being served to create links to the other available representations. As an example, when using HTML, one might use a and link elements to advertize the availability of alternate representations. In this context, note that there are two distinct types of such links: Links for human consumption that are to be presented to the user And links for machine consumption, that are used by the user agent to provide additional functionality. As an example, links to available alternatives meant for human consumption might use the HTML a element since these are rendered by user-agents. In contrast, links meant for use by bots might use the HTML link element — as an example, this reflects present practice when publishing pointers to Atom/RSS feeds.

In either case, notice that following these steps creates a mini-graph comprising of the canonical URI and URIs for its various representations.