The 'actuate' attribute is used to communicate the desired timing 
        of traversal from the starting resource to the ending resource; 
        it's value should be treated as follows:
        onLoad - traverse to the ending resource immediately on loading 
                 the starting resource 
        onRequest - traverse from the starting resource to the ending 
                    resource only on a post-loading event triggered for 
                    this purpose 
        other - behavior is unconstrained; examine other markup in link 
                for hints 
        none - behavior is unconstrained

The 'show' attribute is used to communicate the desired presentation 
        of the ending resource on traversal from the starting resource; it's 
        value should be treated as follows: 
        new - load ending resource in a new window, frame, pane, or other 
              presentation context
        replace - load the resource in the same window, frame, pane, or 
                  other presentation context
        embed - load ending resource in place of the presentation of the 
                starting resource
        other - behavior is unconstrained; examine other markup in the 
                link for hints 
        none - behavior is unconstrained