xlinks.xsd see GML 7.2 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 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