Oracle Solaris 10 9/10: Starting with this release, the itu utility has been modified to support booting a SPARC based system with Install-Time Updates (ITUs). Third-party vendors can now deliver driver updates on floppy disk, CD or DVD, and USB storage. In addition, new tools that enable you to modify the Oracle Solaris installation media with new packages and patches have been introduced. These tools can be used to deliver software updates for hardware platforms and to produce customized installation media. For task-related information, see SPARC: How to Boot a System With a Newly Created ITU.
See also the following man pages: