This pipeline is called just before executing the function that totally deletes the database tables from within the private zone via the ecrire/?exec=admin_effacer page. It is a trigger: a pipeline which simply takes note of an event, without any parameters being passed. As such this pipeline might be renamed as trig_delete_tables in the future.
pipeline('delete_tables', '');There isn’t any particularly interesting application of this pipeline within the plugins available on SPIP Zone. It might be possible to use it to execute processes on an external database when a SPIP site is reinitialised using the admin page, or also to send notifications of the purge action (and perhaps the current admin user’s connection details) to certain nominated recipients as an audit.