Using a post-install script for your extension can serve a number of purposes:

  • Internal revision tracking (if you need this information for updates)
  • Installing default data into your extension's tables (only table structure is moved over in the installation process)
  • Requesting user configuration (you can use the install script to redirect to your extension's settings page)

Your post-install script should exist as "install.php" residing in your extension's base directory.