Content handler actions give invoking applications a choice about how to handle content. An Action is associated with an existing content handler. An image viewer content handler, for example, might include an action for viewing the image at its original size and another action that makes the image fill the available screen space.
In the Projects window, right-click on a project and choose Properties from the context menu. In the Category pane, select Application Descriptor, and click the Content Handler tab. Press Add or Edit to open the Content Handler Properties window and click on the Actions tab, as shown here.
The Actions list contains the internal names of the actions for this content handler. Locales is a list of all the locales for which human-readable action names will be provided. Localized actions is a grid which contains the human-readable action names for various locales. Each locale is represented by a row, while the actions are listed as columns. You can see all the human-readable action names for a particular locale by reading across a single row.