is a a special form of association.
An action key used in WCMF. An action key associates two controllers (to define a control flow) or a view with a controller (to define a view attachment). Controller, Views and Associations define the application flow.

WCMFActionKeys are directional and connect two WCMFControllers or one WCMFView and one WCMFController, respectively.

Contains the following taggedvalues:
action
The action, which is triggered by this association
context
The context, in which this association is valid
config
The configuration file, in which this association will be placed

The declaration of the tagged values action and context is optional. When they're not declared, it basically means "after any action do ..." and "in any context do ...".