Interchange allows you to create "virtual pages" by associating code (such as Perl subroutines or ITL tags) with parts of an URL. This can be used for anything from implementing one-click searches and orders to displaying on-the-fly data.

On every catalog access, the leading part of a requested URL is taken and checked if it represents a valid action. If it does, the action is invoked with the rest of the arguments provided in the URL.

Some of the predefined actions (which you might recognize from special page names that you access in your catalog) are:

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