Assigning Aliases and Redirects

Drupal assigns exactly one numeric node-id to each piece of content on the site.  This ID can always be used to access content.  For example, the node ID of this page is 6370.  Users can always access this page using the following URL:  http://marinemetadata.org/node/6370 .

However, this URL is not graceful or memorable, and it does not provide any information about the content.  To achieve these goals, the MMI project makes use of Aliases and Redirects. 

An Alias is an alternate URL for a piece of content.  In the case of this page, the alias is http://marinemetadata.org/help/tech/alias. Our installation of Drupal provides a 'main alias', which is the one that is displayed in the browser's address bar; we would like the main alias to be the best known path for the content (see below). In any case, a good practice is to avoid multiple aliases to the same page, as this may confuse people and search engines. 

A Redirect sends visitors from the originally requested URL to a 'more correct' URL. The Drupal installation, like most web hosts, can also provide information about why the redirect has been created; for example, a '301' redirect indicates the page has been permanently moved. By using these redirects, search engines and other tools understand that a redirected URL is not the 'correct' address of the page, but is merely a way to get to the page.

Procedures for Aliases and Redirects on the MMI Site

The following 'best practices' have been established as routine procedures for working with content on the MMI site.

• Aliases should never be simply removed (since something is probably pointing to them); they should be converted to redirects. Redirects should not be removed.
• A node should have exactly one alias, but can have multiple redirects.
  If, in the process of editing a page, multiple aliases are discovered, all but the main alias should be converted to redirects using the "Path Aliases" tab.
• The primary alias for each node should follow the procedure for naming aliases.
• Nodes without aliases may not be referenced, and so may not be discoverable by search engines. (While the same may be true of aliased nodes, it is more likely that an alias will point to that page.)
• Aliases and Redirects should be pointed to the node/#### form of the URL, not to the alias or redirect.
  In other words, redirects to this page should point to node/6370, not /help/tech/alias.