When patrons enter their surname and firstname in the self-registration form they sometimes don’t capitalize the first letter of their names. It would improve accuracy if whatever they enter in these fields was transformed to begin with a capital letter. Since all of our patrons register for their cards using the self-registration form, it would also be more efficient for our staff as well since we correct any errors we find.
Although relatively rare in my experience, there are still cases where the user would not want their entry to be transformed. The example surname that comes to mind is something like "da Silva."
I think this kind of thing would be better handled by a plugin or by custom JavaScript.