persistent_variable

Matches the value of the persistent variable if the "view" view of the "content" module was executed. (The persistent variable should be set in the "node/view/<view_mode>.tpl" template that was used by this view.)

error_number

Matches kernel errors. Note that some kind of errors, i.e. database errors, may prevent the overriding.

[any]

The pagelayout may be overridden using the same keys that are available for the view which was used within the request. For example, if the "view" view of the "content" module was accessed, then the override conditions of that view will be matched. This makes it possible to create a pagelayout override that will be triggered when, for example, nodes referencing objects that belong to a certain section are requested.